Over the first decade of this century, record high daily temperatures in the U.S. were registered twice as often as record lows, a clear sign of global warming. If emissions of heat-trapping greenhouse gases continue on their current track, that ratio could become even more skewed, potentially reaching 15-to-1 by midcentury, a new study finds.

New research shows that climate change may impede the cooling effect of volcanic eruptions. When an eruption is powerful enough, volcanoes spew sulfur gasses high into the atmosphere, 10 to 15 kilometres above Earth's surface. Here, gasses react with water to form aerosol particles that linger in the stratosphere for one or two years, reflecting sunlight and heat from the sun, and cooling the planet. "[B]ut as the planet heats up and our atmosphere changes, we've found that fewer eruptions will be able to reflect the sun's radiation," said a scientist who specializes in climate and volcanoes.

The world is set to notch up a new heat record in 2016 after a sizzling 2015 as global warming stokes more floods and rising sea levels, the U.N. weather agency said on Monday at climate change talks overshadowed by Donald Trump's election win.

President-elect Trump has called climate change a hoax and a source in his transition team says he is seeking quick ways to pull the United States out of the 2015 Paris Agreement, which aims to shift the world economy away from fossil fuels towards renewable energy.

If leading scientists writing in one of the most respected academic journals are right, planet Earth could be on course for global warming of more than seven degrees Celsius within a lifetime. That, according to one of the world’s most renowned climatologists, could be “game over” – particularly given the imminent presence of climate change denier Donald Trump in the White House. According to the current best estimate, by the Intergovernmental Panel on Climate Change (IPCC), if humans carry on with a “business as usual” approach using large amounts of fossil fuels, the Earth’s average temperature will rise by between 2.6 and 4.8 degrees above pre-industrial levels by 2100.

Warming in the Arctic is thought to be influencing the jet stream, a high-altitude corridor of fast-moving air, leading to severe cold snaps. It may have been responsible for record snowfall in New York during the winter of 2014/15, and unusually cold winters in the UK in 2009/10 and 2010/11. When the jet stream follows a “wavy” irregular path there are more cold weather fronts plunging south from the Arctic into mid-latitudes, bringing freezing conditions that persist for weeks at a time. When the jet stream flows steadily from west to east, winter weather in the UK and other countries in the temperate belt between the tropics and the Arctic is milder.

Levels of CO2 in the atmosphere have surged past an important threshold and may not dip below it for "many generations". The 400 parts per million benchmark was broken globally for the first time in recorded history in 2015. But according to the World Meteorological Organisation (WMO), 2016 will likely be the first full year to exceed the mark. The last time CO2 was regularly above 400ppm was three to five million years ago, say experts.

The global temperature has increased to a level not seen for 115,000 years, requiring daunting technological advances that will cost the coming generations hundreds of trillions of dollars, according to the scientist widely credited with bringing climate change to the public’s attention. A new paper submitted by James Hansen, a former senior Nasa climate scientist, and 11 other experts states that the 2016 temperature is likely to be 1.25C above pre-industrial times, following a warming trend where the world has heated up at a rate of 0.18C per decade over the past 45 years.

A pattern of warm and dry winters in the West, paired with frigid conditions in the East, has become more frequent since 1980, a trend that reflects the influence of global warming on the atmosphere in the Northern Hemisphere. The pattern has been costly, including a multi-year drought in California and economically disruptive snowstorms in the Northeast. The past two years—Earth's warmest years on record—brought the greatest East-West temperature contrasts in the observational record. The coolest Eastern winter on record and the warmest Western winters since at least 1980 have all been recorded since 2013, the study found.

The planet is warming at a pace not experienced within the past 1,000 years, at least, making it “very unlikely” that the world will stay within a crucial temperature limit agreed by nations just last year, according to Nasa’s top climate scientist. This year has already seen scorching heat around the world, with the average global temperature peaking at 1.38C above levels experienced in the 19th century, perilously close to the 1.5C limit agreed in the landmark Paris climate accord. July was the warmest month since modern record keeping began in 1880, with each month since October 2015 setting a new high mark for heat.

The world is careening towards an environment never experienced before by humans, with the temperature of the air and oceans breaking records, sea levels reaching historic highs and carbon dioxide surpassing a key milestone, a major international report has found. The “state of the climate” report, led by the National Oceanic and Atmospheric Administration (Noaa) with input from hundreds of scientists from 62 countries, confirmed there was a “toppling of several symbolic mileposts” in heat, sea level rise and extreme weather in 2015.

Scientists at NASA released their first-ever mid-year analysis of climate trends, which revealed that every month between January and June had the warmest average temperature on record for that month. NASA researchers did this new analysis "mainly because the average temperatures for the first half of this year are so in excess of any first part of the year that we've seen," said NASA scientist Gavin Schmidt. When comparing this year's temperature trends with past years, Schmidt said 2015 was also a very warm year, "but 2016 really has blown that out of the water."

The series of smashed global records, particularly the extraordinary heat in February and March, has provoked a stunned reaction from climate scientists, who are warning that climate change has reached unprecedented levels and is no longer only a threat for the future. Alongside the soaring temperatures, other records have tumbled around the world, from vanishing Arctic sea ice to a searing drought in India and the vast bleaching of the Great Barrier Reef.

In the remote reaches of Antarctica, the South Pole Observatory carbon dioxide observing station cleared 400 ppm on May 23, according to an announcement from the National Oceanic and Atmospheric Administration on Wednesday. That’s the first time it’s passed that level in 4 million years.

Scientists who measure and forecast the concentrations of greenhouse gases in the atmosphere said that we may have passed a key turning point. Humans walking the Earth today will probably never live to see carbon dioxide concentrations in the atmosphere once again fall below a level of 400 parts per million.

The world is hurtling towards an era when global concentrations of carbon dioxide never again dip below the 400 parts per million (ppm) milestone, as two important measuring stations sit on the point of no return. The news comes as one important atmospheric measuring station at Cape Grim in Australia is poised on the verge of 400ppm for the first time. Sitting in a region with stable CO2 concentrations, once that happens, it will never get a reading below 400ppm. Meanwhile another station in the northern hemisphere may have gone above the 400ppm line for the last time, never to dip below it again.

Climate science has progressed so much that experts can accurately detect global warming’s fingerprints on certain extreme weather events. For years scientists have given almost a rote response to the question of whether an instance of weird weather was from global warming, insisting that they can’t attribute any single event to climate change. When it comes to heat waves, droughts, heavy rain, and some other events, scientists can now detemine whether they were more likely or more severe because of man-made global warming.

The annual growth rate of carbon dioxide in the atmosphere rose more in 2015 than scientists have ever seen in a single year, the National Oceanic and Atmospheric Administration announced. It was the fourth year in a row that carbon dioxide concentrations grew by more than 2 parts per million, with an annual growth rate of 3.05 parts per million in 2015. ­The spike comes in the same year that Earth reached an ominous global warming milestone -- scientists last year measured the highest atmospheric concentrations of carbon dioxide ever recorded. As of February, the average atmospheric carbon dioxide concentration in the earth’s atmosphere was about 402.6 ppm.

Global warming went into overdrive in January, leading to astounding temperature records. January was the globe's most unusually warm month ever recorded, and the past three months have been the most unusually warm three-month period on record as well, according to new findings from NASA. January was also the warmest such month on record, NASA found, in preliminary data released this weekend by the Goddard Institute for Space Studies (GISS) in New York.

If humans don’t cut carbon emissions soon, the Earth could feel the catastrophic impact for tens of thousands of years, a new study has found. Researchers from an array of universities in the United States and Europe suggest that the consequences of fossil fuels burned today could last well beyond 2100 – and the study is meant to urge policymakers to act with that perspective in mind.

During the next week, the official climate agencies around the world that are responsible for tracking the planet's average temperatures will almost certainly come to the same conclusion: 2015 was the warmest year on record. The combination of a record strong El Niño event plus the highest amount of greenhouse gases in the atmosphere at any time in human history have given the climate system the equivalent of a Power Bar plus a shot of espresso. On Wednesday, one unofficial temperature tracking group, known as Berkeley Earth, revealed its determination that 2015 was by far the planet's warmest year, both on land and sea.

Mankind is pumping so much carbon dioxide into the atmosphere that it could postpone the next ice age by more than 100,000 years, according to new research which finds humans are having a “mind-boggling” impact on the Earth. The volume of CO2 emissions that has accumulated in the atmosphere is so great that it has fundamentally changed the relationship between people and the planet as human behaviour radically alters the way the system operates. The study found that the next ice age would be pushed back by about 50,000 years even if emissions stopped overnight. If the volume of greenhouse gases forecast to be produced in the coming decades comes to pass it could be postponed by more than 100,000 years.

Cyclical changes in the Pacific Ocean have thrown earth’s surface into what may be an unprecedented warming spurt, following a global warming slowdown that lasted about 15 years. While El Niño is being blamed for an outbreak of floods, storms and unseasonable temperatures across the planet, a much slower-moving cycle of the Pacific Ocean has also been playing a role in record-breaking warmth. The recent effects of both ocean cycles are being amplified by climate change. A 2014 flip was detected in the sluggish and elusive ocean cycle known as the Pacific Decadal Oscillation which scientists link its 2014 phase change to a rapid rise in global surface temperatures.

The first half of the 2010s will be remembered for its record heat. The five-year period from 2011-15 has been the hottest such period ever recorded. And with last year setting the hottest year mark, only to be surpassed by a wide margin this year, it’s clear that the planet has changed.

Greenhouse gas levels in the atmosphere reached a record high in 2014 and the relentless fuelling of climate change is endangering the planet for future generations, the World Meteorological Organization said. Graphs issued by the WMO, a U.N. agency, showed levels of carbon dioxide, the main greenhouse gas, climbing steadily towards the 400-parts-per-million (ppm) level, having hit a new record every year since reliable records began in 1984. Carbon dioxide levels averaged 397.7 ppm in 2014 but briefly breached the 400-ppm threshold in the northern hemisphere in early 2014, and again globally in early 2015.

From a deadly snowstorm in Nepal to a heat wave in Argentina that crashed power supplies, at least 14 extreme weather events last year bore the fingerprints of human-induced climate change, an international team of scientists reported. Researchers examined 28 weather extremes on all seven continents to see if they were influenced by climate change or were just normal weather. Their conclusion: Half of them showed some role of climate change.

The world is currently in a period of mass extinction, according to a new study. Human activities have been linked to the falling populations of many species but the research also warns that extinction on a large scale could threaten human existence. The study, which has been published in Science Advances, calls for fast actions to protect threatened species, populations and habitat. It estimates that species are disappearing up to about 100 fasters than the normal rate between mass extinctions, known as the background rate.

Climate change may be the driving force behind fewer, yet more powerful hurricanes and tropical storms, says a Florida State geography professor. In a paper published today by Nature Climate Change, researchers found that rising ocean temperatures are having an effect on how many tropical storms and hurricanes develop each year. "We're seeing fewer hurricanes, but the ones we do see are more intense," Prof. Jim Elsner said. "When one comes, all hell can break loose."

The National Oceanic and Atmospheric Administration says in March, the global monthly average for carbon dioxide hit 400.83 parts per million. That is the first month in modern records that the entire globe broke 400 ppm, reaching levels that haven't been seen in about 2 million years.

The world is likely to build so many fossil-fuelled power stations, energy-guzzling factories and inefficient buildings in the next five years that it will become impossible to hold global warming to safe levels, and the last chance of combating dangerous climate change will be "lost for ever", according to the International Energy Agency. Anything built from now on that produces carbon will do so for decades, and this "lock-in" effect will be the single factor most likely to produce irreversible climate change, the world's foremost authority on energy economics has found. If this is not rapidly changed within the next five years, the results are likely to be disastrous.

Blame global warming for about 75 percent of the world’s unusually hot days and 18 percent of its extreme snow or rain, according to a new paper in the journal Nature Climate Change. Heat waves and heavy storms are occurring at least four times more often than they did before carbon pollution started driving up thermometers. Global average temperatures are now about 0.85 degrees Celsius (1.4 Fahrenheit) higher than before industrialization.

World leaders must reduce the long-held target of limiting global warming to below two degrees Celsius to avoid catastrophic impacts on the world's poorest people, says a leading climate scientist. Industrialised nations must stop ignoring the sustained calls from the developing world - backed by scientists - and set a 1.5 degree cap when the internationally agreed limit comes under review at UN climate talks later this year in Paris, France, says Petra Tschakert, a geographer from Pennsylvania State University.

A recent study published in the journal Science details how Arctic warming is essentially putting the brakes on atmospheric circulation in mid-latitudes, leaving North America and Europe with uncharacteristically strong heat waves.

The new year has only just begun, but we’ve already recorded our first days with average carbon dioxide levels above 400 parts per million, potentially leading to many months in a row above this threshold, experts say. While the 400 ppm mark is somewhat symbolic (as the increase in warming between 399 ppm and 400 ppm is small), it is a large increase from pre-industrial CO2 concentrations, which were around 280 ppm. The progressively earlier occurrence of these high CO2 levels — not seen in somewhere between 800,000 and 15 million years — points to the inexorable buildup of heat-trapping gas in the atmosphere.

Small volcanic eruptions may have been slowing global warming for over a decade, according to a new study with results that are in line with previous findings that vast quantities of ash and gases ejected from volcanoes can have a remarkable cooling effect on Earth’s climate by blocking solar radiation. According to scientists, the effects of such volcanic eruptions may explain why the warming of the planet has slowed down in recent years, falling short of matching levels predicted by scientists based on the amount of carbon entering the atmosphere, Discovery News reported, adding that small-scale ejections could be responsible for almost halving the rate of global warming.

So 2014's December may have been bone-chillingly cold for some parts of the world, but when measurements from every corner of the Earth from Jan. 1 to Dec. 31 were finally combined and averaged, it was revealed that this past year was easily the hottest ever recorded. That's according to Japan''s Meteorological Agency, one of the four primary record-keeping organizations that routinely measure, gather, and assess net temperature data from across the globe. This data includes both terrestrial and water surface temperatures, which - as shown by this past record-breaking summer being driven by a warming ocean - can vary significantly.

New research shows that CO2 brings peak heat within a decade of being emitted, with the effects then lingering 100 years or more into the future. The research, published in Environmental Research Letters, provides policymakers and economists with a new perspective on how fast human carbon emissions heat the planet. Back-of-the-envelope estimates for how long it takes for a given puff of CO2 to crank up the heat have generally been from 40-50 years. But the new study shows that the timeframe for CO2 emissions to reach their maximum warming potential is likely closer to 10 years.

While severe weather like hurricanes and tornadoes typically only hit particular areas of the globe, lightning can strike anywhere. And it does, a lot. A bolt of lightning flashes through the sky and hits the ground somewhere around the world about 100 times every second. That’s 8 million lightning strikes in a single day — yes, you read that right: just one day. Now, a new study finds that lightning strikes will become even more frequent as the planet warms, at least in the continental U.S.

Global greenhouse emissions will need to fall to zero by the end of this century if the world is to avoid the most devastating impacts of climate change, according to the UN’s leading scientists. In its latest report, released today in Copenhagen, the Intergovernmental Panel on Climate Change (IPCC) also calls for the unrestricted use of coal, oil and gas to be phased out by 2100.

In the latest study to look at the possible connection between the precipitous decline of Arctic sea ice and extreme weather over the Northern Hemisphere, researchers found that cold winters over Europe and Asia were twice as likely thanks to sea ice decline in a particular part of the Arctic. A new study was able to find a connection by conducting a large number of computer model simulations and determining there is a link between sea ice decline and cold winters over Europe and Asia, at least.

Climate change may have "serious, pervasive and irreversible" impacts on human society and nature, according to a draft U.N. report due for approval this week that says governments still have time to avert the worst. Delegates from more than 100 governments and top scientists meet in Copenhagen on Oct 27-31 to edit the report, meant as the main guide for nations working on a U.N. deal to fight climate change at a summit in Paris in late 2015. They will publish the study on Nov. 2.

The savage heat waves that struck Australia last year were almost certainly a direct consequence of greenhouse gases released by human activity, researchers said Monday. It is perhaps the most definitive statement climate scientists have made tying a specific weather event to global warming. Five groups of researchers, using distinct methods, analyzed the heat that baked Australia for much of 2013 and continued into 2014, briefly shutting down the Australian Open tennis tournament in January when the temperature climbed to 111 degrees Fahrenheit. All five research groups came to the conclusion that last year’s heat waves could not have been as severe without the long-term climatic warming caused by human emissions.

Just days after NASA data showed that August 2014 was the warmest August on record, the National Oceanic and Atmospheric Administration confirmed the ranking and raised the ante: There’s a good chance 2014 could become the warmest year on record. which ranks as the 3rd warmest such period on record. Specifically, if each of the remaining months of the year ranks among the top five warmest, 2014 will take the top spot.

Surging levels of carbon dioxide sent greenhouse gases in the atmosphere to a new record in 2013, while oceans, which absorb the emissions, have become more acidic, the UN said. Concentrations of carbon dioxide (CO2), methane and nitrous oxide all broke fresh records in 2013, said the report. Global concentrations of CO2, the main culprit in global warming, soared to 396 parts per million last year, or 142 percent of pre-industrial levels -- defined as before 1750. That marked a hike of 2.9 parts per million between 2012 and 2013 alone -- the largest annual increase in 30 years, according to the Greenhouse Gas Bulletin.

Due to global warming, a megadrought is likely in store for the southwestern United States in the future, researchers say. According to a new study, the chances that this region will experience a decade-long drought is at least 50 percent, and the odds of a "megadrought" - one that lasts over 30 years - ranges from 20 to 50 percent over the next century.

Global warming is here, human-caused and probably already dangerous – and it’s increasingly likely that the heating trend could be irreversible, a draft of a new international science report says. The Intergovernmental Panel on Climate Change sent governments a final draft of its synthesis report, which combines three earlier, gigantic documents by the group. There is little in the report that wasn’t in the other more-detailed versions, but the language is more stark and the report attempts to connect the different scientific disciplines studying problems caused by the burning of fossil fuels, such as coal, oil and gas.

As people clean up after torrential rains and heavy flooding in cities in the Midwest and along the Atlantic Coast, the events highlight what many climate researchers say is a new "normal" for severe rainfall in the US. Quite apart from what long-term changes in precipitation say about global warming, these events also provide a reality check on the ability of urban areas to cope with flooding from intense downpours in a warming climate.

"Our analysis demonstrates that the upper-tropospheric moistening observed over the period 1979–2005 cannot be explained by natural causes and results principally from an anthropogenic warming of the climate. By attributing the observed increase directly to human activities, this study verifies the presence of the largest known feedback mechanism for amplifying anthropogenic climate change."

Scientists have linked the rapid rise in Arctic temperatures over the past two decades to weather extremes in the northern hemisphere such as heatwaves in the US and flooding in Europe. Temperatures in the Arctic have risen twice as fast as the rest of the world since 2000, and this could have triggered changes to global wind patterns, which have brought extreme weather to lower latitudes. A study has found that the number of extreme weather events, such as heatwaves, floods and droughts, has almost doubled over the same period and that this increase can be linked with unusual wind patterns in the upper atmosphere, influenced by warmer Arctic temperatures.

The latest fifth assessment report of the Inter-Governmental Panel on Climate Change (IPCC) predicts a bleak future for the world, and especially South Asia. Hinting that it may already be too late for significant course correction on global warming, the report cautions, “Regardless of action taken now to reduce emissions, the climate will change until around the middle of this century.” Urgent damage control and risk mitigation are the need of the hour, the report notes.

Climate data compiled by 425 scientists from 57 countries indicate that global temperatures in 2013 continued their long-term rising trend. Moreover, the planet ranged well outside of normal levels in 2013, hitting new records for greenhouse gases, Arctic heat, warm ocean temperatures and rising sea levels. According to the study, 2013 was somewhere between the second- and sixth-hottest year on record for the planet since record keeping began in 1880. (Four groups of scientists, who rely on slightly different methods to calculate global surface temperatures, ranked 2013 slightly differently compared with other years.)

Scientists at the National Oceanic and Atmospheric Administration’s Mauna Loa observatory in Hawaii told Climate Central that June would be be the third month in a row where, for the entire month, average levels of carbon dioxide were above 400 parts per million (ppm). In other words, that’s the longest time in recorded history that this much carbon dioxide has been in the atmosphere.

After an early spring and summer, the year is now racing towards autumn ahead of schedule, conservationists have said. As the year reached the half-way mark, the National Trust said wildlife seemed to have come through the wettest and stormiest winter on record and nature had hurtled "helter-skelter" through the seasons since.

Researchers found that forests throughout the eastern United States are showing signs of spring growth earlier than ever, and the growing season in some areas extends further into the fall. Other than the fact that some get to enjoy a much-welcomed prolonged spring, the expanded growing season has also allowed forests to store as much as 26 million metric tons more carbon dioxide (CO2) than before. Yet, researchers remind us that this is just one small upside to climate change, and does in no way outweigh its many negative affects.

The acid test of a scientific theory is whether it makes predictions that eventually come true. So consider this old prediction, from a pair of researchers in Australia and New Zealand. They were summarizing the results of then-primitive computerized forecasts about global warming. “The available evidence suggests that a warmer world is likely to experience an increase in the frequency of heavy precipitation events, associated with a more intense hydrological cycle and the increased water-holding capacity of a warmer atmosphere.” That was published in 1995, and it was based on research going back to the 1980s. Fast forward to 2014. In the National Climate Assessment, published last week, researchers in the United States reported that “large increases in heavy precipitation have occurred in the Northeast, Midwest and Great Plains, where heavy downpours have frequently led to runoff that exceeded the capacity of storm drains and levees, and caused flooding events and accelerated erosion.”

The effects of human-induced climate change are being felt in every corner of the United States, scientists reported Tuesday, with water growing scarcer in dry regions, torrential rains increasing in wet regions, heat waves becoming more common and more severe, wildfires growing worse, and forests dying under assault from heat-loving insects. Such sweeping changes have been caused by an average warming of less than 2 degrees Fahrenheit over most land areas of the country in the past century, the scientists found. If greenhouse gases like carbon dioxide and methane continue to escalate at a rapid pace, they said, the warming could conceivably exceed 10 degrees by the end of this century.

There has been no reverse in the trend of global warming and there is still consistent evidence for man-made climate change, the head of the U.N. World Meteorological Organisation (WMO) said. U.N. weather agency chief Michel Jarraud said ocean temperatures, in particular, were rising fast, and extreme weather events, forecast by climate scientists, showed climate change was inevitable for the coming centuries.

Two Union of Concerned Scientists (UCS) climate scientists and two colleagues argue that policymakers need to acknowledge that the world is already on track for warming beyond 2°C. "A policy narrative that continues to frame this target as the sole metric of success or failure to constrain climate change risk is now itself becoming dangerous," they wrote. "[It] ill-prepares society to confront and manage the risks of a world that is increasingly likely to experience warming well in excess of 2°C this century,"

Despite reports of a global warming "hiatus," a new study shows that the number of areas being affected by extreme heat are on the rise and that the hottest temperatures on the planet are also increasing. “. . . [T]he frequency of hot extremes over land has continued to increase in the last 15 years, despite an apparent stabilization of the global mean temperature,” the study concluded.

Scientists call it Santa’s revenge. It’s the theory that persistent weather patterns at the mid-latitudes – like this winter’s tediously long-lasting polar vortex or California’s severe drought – are a direct consequence of climate change heating up the Arctic. New evidence suggests the link is real, even as experts continue to argue over how much it is influencing the weather on a day to day basis. The effect has implications for severe weather predictions, food security and water use across the northern hemisphere. If the data are right, they suggest that climate change in the Arctic is coming home to roost in a big and expensive way.

Last year was the thirty-seventh consecutive year of above-normal global temperature. According to data from NASA, the global temperature in 2013 averaged 58.3 degrees Fahrenheit (14.6 degrees Celsius), roughly a degree warmer than the twentieth-century average. Since the dawn of agriculture 11,000 years ago, civilization has enjoyed a relatively stable climate. That is now changing as the growing human population rivals long-range geological processes in shaping the face of the planet. Fully 4 billion people alive today have never experienced a year that was cooler than last century’s average, begging the question of what is now “normal” with respect to the climate.

A bitter Arctic blast spanning the central and eastern US has propelled the phrase "polar vortex" from the pages of dense scientific papers to headline status as frigid temperatures and strong winds close schools and businesses and prompt forecasters to warn of "historic and life-threatening" conditions. Paradoxically, the event may be a harbinger of winter outbreaks to come in the northern hemisphere as Earth's climate warms, some researchers say – a result of shrinking Arctic Ocean summer sea ice and the projected changes in wind and snowfall patterns triggered by the ocean's warmth and moisture.

Continued global warming poses a risk of rapid, drastic changes in some human and natural systems, a scientific panel warned, citing the possible collapse of polar sea ice, the potential for a mass extinction of plant and animal life and the threat of immense dead zones in the ocean. The panel appointed by the National Research Council called for the creation of an early warning system to alert society well in advance to changes capable of producing chaos. Nasty climate surprises have occurred already, and more seem inevitable, perhaps within decades, panel members warned. But, they said, little has been done to prepare.

An internationally agreed target to limit rises in global average temperatures to within 2 degrees Celsius is around double the threshold that would avoid catastrophic climate change, a study by 18 eminent scientists said. A study published in the scientific journal PLOS One said the 2 degree limit was too high and a more appropriate target was around 1 degree C. "Some climate extremes are already increasing in response to warming of several tenths of a degree in recent decades; these extremes would likely be much enhanced with warming of 2 degrees C or more," the report's authors said in a statement.

The Arctic methane time bomb is bigger than scientists once thought and primed to blow, according to a study published today (Nov. 24) in the journal Nature Geoscience. About 17 teragrams of methane, a potent greenhouse gas, escapes each year from a broad, shallow underwater platform called the East Siberian Arctic Shelf, said the lead author of the study. A teragram is equal to about 1.1 million tons; the world emits about 500 million tons of methane every year from manmade and natural sources. The new measurement more than doubles the team's earlier estimate of Siberian methane release, published in 2010 in the journal Science.

A global analysis of current climate policies and pledges to cut emissions indicates that temperatures may rise by as much as 3.7 degrees celsius by end of the century—well over the so-called 'safe' warming target of two degrees the world set for itself in the Copenhagen Accord of 2009. The Climate Action Tracker, released at that UN Climate Conference in Warsaw today, has concluded that on current trends, the world is headed for almost four degrees of warming.

The chances of keeping the global temperature increase below 2C will “swiftly diminish” unless the world takes immediate action to escalate cuts in carbon emissions, the United Nations has warned. The UN Environment Program said that even if nations meet their current emissions reduction pledges, carbon emissions in 2020 will be eight to 12 gigatonnes above the level required to avoid a costly nosedive in greenhouse gas output. The Emissions Gap Report 2013, which was compiled by 44 scientific groups in 17 countries, warns that if the greenhouse “gap” isn’t “closed or "significantly narrowed” by 2020, the pathway to limiting the global temperature rise to 1.5C will be closed.

The world is hurtling toward a stark future where the web of life unravels, human cultures are uprooted, and millions of species go extinct, according to a new study. This doomsday scenario isn't far off, either: It may start within a decade in parts of Indonesia, and begin playing out over most of the world — including cities across the United States — by mid-century. What's more, even a serious effort to stabilize spiraling greenhouse gas emissions will only stave off these changes until around 2069, notes the study from the University of Hawaii, Manoa, published online Wednesday in the journal Nature. The authors warn that the time is now to prepare for a world where even the coldest of years will be warmer than the hottest years of the past century and a half.

New research shows that average summer temperatures in the Canadian Arctic over the last century are the highest in the last 44,000 years, and perhaps the highest in 120,000 years. The study is the first to show that current Arctic warmth exceeds peak heat there in the early Holocene, the name for the current geological period, which began about 11,700 years ago. During this "peak" Arctic warmth, solar radiation was about 9 percent greater than today, according to the study.

There is “absolutely” a link between climate change and wildfires, U.N. Climate Chief Christiana Figueres told CNN . Wildfires are raging in a ring around Sydney, Australia, as that country experiences its hottest year on record. “The World Meteorological Organization has not established a direct link between this wildfire and climate change – yet,” Figueres said. “But what is absolutely clear is the science is telling us that there are increasing heat waves in Asia, Europe, and Australia; that there these will continue; that they will continue in their intensity and in their frequency.”

Billions of people could be living in regions where temperatures are hotter than their historical ranges by mid-century, creating a "new normal" that could force profound changes on nature and society, scientists said. Temperatures in an average year would be hotter by 2047, give or take 14 years, than those in the warmest year from 1860-2005 if the greenhouse gas emissions continue to rise, with the tropics the first affected area, a new index indicated. "The results shocked us. Regardless of the scenario, changes will be coming soon," lead author Camilo Mora of the University of Hawaii said. "Within my generation whatever climate we were used to will be a thing of the past."

An international panel of scientists has found with near certainty that human activity is the cause of most of the temperature increases of recent decades, and warns that sea levels could conceivably rise by more than three feet by the end of the century if emissions continue at a runaway pace. The report emphasizes that the basic facts about future climate change are more established than eve

Cutting short-lived emissions such as soot spewed from trucks and methane belched from cattle will do little as a short-term fix for global warming, a new study says. Previous work indicated that such cuts could shave about 1 degree Fahrenheit from warming by 2050, enough to buy the world time to wrench the energy economy away from oil, coal and natural gas — major sources of the long-term heat-trapping gas carbon dioxide. The new research finds the climate benefit of soot and methane cuts is only about 0.3 degree Fahrenheit by midcentury.

A new massive federal study says the world in 2012 sweltered with continued signs of climate change. Rising sea levels, snow melt, heat buildup in the oceans, and melting Arctic sea ice and Greenland ice sheets, all broke or nearly broke records, but temperatures only sneaked into the top 10. The National Oceanic and Atmospheric Administration's report, written by 384 scientists around the world, compiles data already released, but it puts them in context of what's been happening to Earth over decades.

Stanford University climate researchers warn that the likely rate of climate change over the next century will be 10 times faster than the rate of any climate shift in the past 65 million years, meaning the planet will undergo one of the largest changes in climate since the dinosaurs went extinct.

A release of methane in the Arctic could speed the melting of sea ice and climate change with a cost to the global economy of up to $60 trillion over coming decades. Researchers at the University of Cambridge and Erasmus University in the Netherlands used economic modeling to calculate the consequences of a release of a 50-gigatonne reservoir of methane from thawing permafrost under the East Siberian Sea. One of the report's authors called the warming Arctic "an economic time-bomb."

The world is currently on course to exploit all its remaining fossil fuel resources, a prospect that would produce a "different, practically uninhabitable planet" by triggering a "low-end runaway greenhouse effect." This is the conclusion of a new scientific paper by Prof James Hansen, the former head of NASA's Goddard Institute for Space Studies and the world's best known climate scientist.

The world suffered unprecedented climate extremes in the decade to 2010, from heatwaves in Europe and droughts in Australia to floods in Pakistan, against a backdrop of global warming, a United Nations report said. Every year of the decade except 2008 was among the 10 warmest since records began in the 1850s, with 2010 the hottest, according to the study by the World Meteorological Organization (WMO). The number of daily heat records far outstripped lows.

Some of the most extreme predictions of global warming are unlikely to materialise, new scientific research has suggested, but the world is still likely to be in for a temperature rise of double that regarded as safe. The researchers said warming was most likely to reach about 4C above pre-industrial levels if the past decade's readings were taken into account. That would still lead to catastrophe across large swaths of the Earth, causing droughts, storms, floods and heatwaves, and drastic effects on agricultural productivity leading to secondary effects such as mass migration.

Temperatures are rising faster today than they have at any point since at least the end of the last ice age, about 11,000 years ago, according to a new study. The finding is based on a global reconstruction of temperature records inferred from ice cores, fossils in ocean sediments and other sources. While previous studies reached similar conclusions, they covered only about 2,000 years. The new reconstruction extends the global record through the Holocene, the most recent geologic epoch.

Don’t count on sulfur dioxide to bridle climate change. The ability of that pollutant to reflect the sun is not quite what it was assumed to be, according to new research. Scientists at the Max Planck Institute for Chemistry now say that climate models probably overstate the cooling effect. They highlighted an often-overlooked chemical process involving mineral dust in clouds that affects the lifespan of sulfate aerosol particles.

The level of the most important heat-trapping gas in the atmosphere, carbon dioxide, has passed a long-feared milestone, scientists reported Friday, reaching a concentration not seen on the earth for millions of years. Scientific instruments showed that the gas had reached an average daily level above 400 parts per million — just an odometer moment in one sense, but also a sobering reminder that decades of efforts to bring human-produced emissions under control are faltering. The best available evidence suggests the amount of the gas in the air has not been this high for at least three million years, before humans evolved, and scientists believe the rise portends large changes in the climate and the level of the sea.

The world's carbon dioxide levels are on the cusp of reaching 400 parts per million in the atmosphere for the first time in 3 million years. The daily CO2 level, measured at the Mauna Loa Observatory in Hawaii, stood at 399.72 parts per million last Thursday, and a few hourly readings had already risen above 400 parts per million. ''I wish it weren't true, but it looks like the world is going to blow through the 400 ppm level without losing a beat,'' ''At this pace we'll hit 450 ppm within a few decades,' 'said Ralph Keeling, of the Scripps Institution of Oceanography in the US, which operates the Hawaiian observatory. The 450 parts per million level is considered the point where the world has a 50 per cent chance of avoiding dangerous climate change - any higher, and the odds of avoiding searing temperature rises of four or five degrees by the end of the century become prohibitively risky.

A global long-term cooling trend ended late in the 19th century and was followed decades later by the warmest temperatures in nearly 1,400 years, a sweeping study of temperature change showed. The study, by a consortium of 78 authors in 24 countries, said its 2,000 years of data made it harder to discount the impact on higher temperatures of increased greenhouse gases due to human activity.

Transatlantic airline passengers might expect to stay seated with their seatbelts securely fastened more often in the future, according to new research that finds climate change could lead to more airplane turbulence. By the middle of the century, turbulence strength over the North Atlantic flight corridor could increase between 10 percent and 40 percent, and turbulence frequency could jump between 40 percent and 170 percent, according to the new study published online Monday in the journal Nature Climate Change.

Climate scientists have linked the massive snowstorms and bitter spring weather now being experienced across Britain and large parts of Europe and North America to the dramatic loss of Arctic sea ice. The heavy snowfall and freezing temperatures which have marked March 2013 across the northern hemisphere are in stark contrast to March 2012 when many countries experienced their warmest ever springs. The hypothesis that wind patterns are being changed because melting Arctic sea ice has exposed huge swaths of normally frozen ocean to the atmosphere would explain both the extremes of heat and cold, say the scientists.

The eruption almost three years ago of an Icelandic volcano added iron to the seas south of the island. But it disappointed hopes that it would help a natural process to remove much carbon dioxide from the atmosphere.

The number of Atlantic storms with magnitude similar to killer Hurricane Katrina, which devastated the U.S. Gulf Coast in 2005, could rise sharply this century, environmental researchers reported. The extreme storms are highly sensitive to temperature changes, and the number of Katrina-magnitude events could double due to the increase in global temperatures that occurred in the 20th century, the researchers reported in the journal Proceedings of the National Academy of Sciences.

Global temperatures are warmer than at any time in at least 4,000 years, scientists reported, and over the coming decades are likely to surpass levels not seen on the planet since before the last ice age. Previous research had extended back roughly 1,500 years, and suggested that the rapid temperature spike of the past century, believed to be a consequence of human activity, exceeded any warming episode during those years. The new work confirms that result while suggesting the modern warming is unique over a longer period. Even if the temperature increase from human activity that is projected for later this century comes out on the low end of estimates, scientists said, the planet will be at least as warm as it was during the warmest periods of the modern geological era, known as the Holocene, and probably warmer than that.

The amount of heat-trapping carbon dioxide in the air jumped dramatically in 2012, making it very unlikely that global warming can be limited to another 2 degrees as many global leaders have hoped, new federal figures show. Carbon dioxide levels jumped by 2.67 parts per million since 2011 to total just under 395 parts per million, according to the National Oceanic and Atmospheric Administration.

Air systems that encircle planet can slow to standstill, as greenhouse gas heats Arctic and causes temperature imbalance.Global warming may have caused extreme events such as a 2011 drought in the United States and a 2003 heatwave in Europe by slowing vast, wave-like weather flows in the northern hemisphere, scientists said on Tuesday.

A warmer atmosphere can hold, and dump, more moisture, snow experts say. And two soon-to-be-published studies demonstrate how there can be more giant blizzards yet less snow overall each year. Projections are that that's likely to continue with man-made global warming.

<span style="font-size:10.0pt;Times New Roman" ;="" color:#242424"="">The world has missed the chance to keep greenhouse gas emissions below the level needed to prevent the temperature climbing above 2° Celsius, according to Robert Watson, the British scientist who chaired the IPCC until 2002. Watson said there is a 50-50 chance of preventing global average temperatures rising more than 3°C above their level at the start of the industrial age, but a 5°C rise is possible. That would mean the Earth warming more than it has since the end of the last Ice Age. <br> </span></div>

Global warming is already changing America from sea to rising sea and is affecting how Americans live, a massive new federally commissioned report says. A special panel of scientists convened by the government issued Friday a 1,146-page draft report that details in dozens of ways how climate change is already disrupting the health, homes and other facets of daily American life. It warns that those disruptions will increase in the future. The blunt report takes a global environmental issue and explains what it means for different U.S. regions, for various sectors of the economy and for future generations.

Last year was among the top 10 warmest in the modern global record, two U.S. climate-watching agencies reported on Tuesday, less than a week after 2012 was declared the hottest ever in the contiguous United States. The U.S. space agency NASA and the National Oceanic and Atmospheric Administration jointly issued two reports on 2012 world temperatures. NASA ranked last year the ninth-warmest since record-keeping began in 1880, while NOAA found last year was the tenth-warmest.

Black carbon, the soot produced by burning fossil fuels and biomass, is a more potent atmospheric pollutant than previously thought, according to a four-year international study. Emitted by diesel engines, brick kilns and wood-fired cookstoves, black carbon is second only to carbon dioxide as the most powerful climate pollutant, according to the study published in the Journal of Geophysical Research-Atmospheres. But because black carbon only lasts in the atmosphere a matter of days, compared to carbon dioxide's atmospheric endurance of centuries, addressing it could be prime target for curbing global warming, the report said.

2012 will go down in history as the hottest year on record in the continental U.S., pushing 1998 into second place. In line with the global warming trend spurred by steadily rising carbon emissions, seven of the top 10 warmest years in the 48 states have occurred in the past 15 years. Like so much recent record-breaking weather, 2012 isn’t just going to top the previous record, 2012 is looking to smash it, by more than 1°F. In mid-December, Climate Central projected that 2012 average temperature for the continental U.S. at 55.34°F compared to the previous record set in 1998 of 54.32°F. For perspective, 1°F is one-quarter of the difference between the coldest and warmest years ever recorded in the U.S.

Carbon dioxide emissions from industry rose an estimated 2.6 percent in a weak global economy this year, powered by rapid emissions growth in China and India, which may add urgency to U.N. climate talks in Doha.The study by the Global Carbon Project, an annual report card on mankind's CO2 pollution, also says emissions grew 3.1 percent in 2011, placing the world on a near-certain path towards dangerous climate change, such as more heat waves, droughts and storms.

The worst U.S. drought in decades has deepened again after more than a month of encouraging reports of slowly improving conditions, a drought-tracking consortium said, as scientists struggled for an explanation other than a simple lack of rain. While more than half of the continental U.S. has been in a drought since summer, rain storms had appeared to be easing the situation week by week since late September. But that promising run ended with Wednesday's weekly U.S. Drought Monitor Report, which showed increases in the portion of the country in drought and the severity of it.

Greenhouse gas levels, which are capable of driving global warming over the coming decades, reached new highs in 2011, according to a new report by the World Meteorological Organization (WMO), a United Nations agency. The volume of carbon dioxide grew by two parts per million (ppm) to reach 390.9 ppm, about 40 percent above the pre-industrial level, the survey said. The survey added that the levels of two other greenhouse gases, methane and nitrous oxide, increased by about 0.3 percent in 2011.

Did climate change cause Hurricane Sandy? Absolutely not. Did climate change have anything to do with Sandy being as bad as it was? Absolutely so, say scientist bloggers whose bread and butter is understanding the physics of our atmosphere. What's more, there is very likely a connection with the storm track of Sandy and the record loss of Arctic Sea ice this year.

Summer temperatures on the Norwegian archipelago of Svalbard in the High Arctic are now higher than during any time over the last 1,800 years, including a period of higher temperatures in the northern hemisphere known as the Medieval Warm Period, according to a new study. In an analysis of algae buried in deep lake sediments, a team of scientists calculated that summer temperatures in Svalbard since 1987 have been 2 to 2.5 degrees Celsius (3.6 to 4.5 degrees F) warmer than during the Medieval Warm Period, which lasted from roughly 950 to 1250 AD.

By many measurements, this summer’s drought is one for the record books. But so was last year’s drought in the South Central states. And it has been only a decade since an extreme five-year drought hit the American West. Widespread annual droughts, once a rare calamity, have become more frequent and are set to become the “new normal.”

This probably comes as no surprise: Federal scientists say July was the hottest month ever recorded in the Lower 48 states, breaking a record set during the Dust Bowl of the 1930s. And even less a surprise: The U.S. this year keeps setting records for weather extremes, based on the precise calculations that include drought, heavy rainfall, unusual temperatures, and storms.

The relentless, weather-gone-crazy type of heat that has blistered the United States and other parts of the world in recent years is so rare that it can't be anything but man-made global warming, says a new statistical analysis from a top government scientist. The research by a man often called the "godfather of global warming" says that the likelihood of such temperatures occurring from the 1950s through the 1980s was rarer than 1 in 300. Now, the odds are closer to 1 in 10, according to the study by NASA scientist James Hansen. He says that statistically what's happening is not random or normal, but pure and simple climate change.

Global carbon emissions from energy are up 48 percent on 1992, when the original Earth summit took place in Rio – a historic summit at which governments agreed to limit emissions in order to prevent dangerous climate change. In 2010, the latest year for which figures have been compiled, the U.S. Energy Information Administration (EIA) said the world emitted 35.1bn tons of carbon from energy consumption. That represents a climb of 6.7 percent on the year before and is significantly higher than the previous best estimate, made by the International Energy Agency last year, that in 2010 a record 33.7bn tons of carbon dioxide were released from burning fossil fuel.

Four major heat records fell in a stunning new climate report from the National Oceanic and Atmospheric Administration (NOAA) on Thursday. The lower 48 states set temperature records for the warmest spring, largest seasonal departure from average, warmest year-to-date, and warmest 12-month period, all new marks since records began in 1895. While the globe has been tracking slightly cooler than recent years — thanks in part to the influence of now dissipated La Nina conditions in the tropical Pacific — the U.S. has been sizzling.

A warmer Earth increases the melting of sea ice during summer, exposing darker ocean water to incoming sunlight. This causes increased absorption of solar radiation and excess summertime heating of the ocean -- further accelerating the ice melt. The excess heat is released to the atmosphere, especially during the autumn, decreasing the temperature and atmospheric pressure gradients between the Arctic and middle latitudes. A diminished latitudinal pressure gradient is associated with a weakening of the winds associated with the polar vortex and jet stream. Since the polar vortex normally retains the cold Arctic air masses up above the Arctic Circle, its weakening allows the cold air to invade lower latitudes.

China spurred a jump in global carbon dioxide (CO2) emissions to their highest ever recorded level in 2011, offsetting falls in the United States and Europe, the International Energy Agency (IEA) said. CO2 emissions rose by 3.2 percent last year to 31.6 gigatonnes, preliminary estimates from the Paris-based IEA showed. China, the world's biggest emitter of CO2, made the largest contribution to the global rise, its emissions increasing by 9.3 percent, the body said, driven mainly by higher coal use.

The last 60 years have been the hottest in Australasia for a millennium and cannot be explained by natural causes, according to a new report by scientists that supports the case for a reduction in manmade carbon emissions. In the first major study of its kind in the region, scientists at the University of Melbourne used natural data from 27 climate indicators, including tree rings, corals and ice cores to map temperature trends over the past 1,000 years.

The number of extreme rainstorms - deluges that dump 3 inches or more in a day - doubled in the U.S. Midwest over the last half-century, causing billions of dollars in flood damage in a trend climate advocates link to a rise in greenhouse gas emissions.

Across the Midwest the biggest storms increased by 103 percent from 1961 through 2011.

The previous 12 months were the warmest in the U.S. since record keeping began in 1895, government scientists reported, with the period averaging 55.7 degrees Fahrenheit — nearly three degrees warmer than the average May-April.

The fragile and rapidly changing Arctic region is home to large reservoirs of methane, a potent greenhouse gas. As Earth's climate warms, the methane, frozen in reservoirs stored in Arctic tundra soils or marine sediments, is vulnerable to being released into the atmosphere, where it can add to global warming. Now a multi-institutional study by Eric Kort of NASA's Jet Propulsion Laboratory, Pasadena, Calif., has uncovered a surprising and potentially important new source of Arctic methane: the ocean itself.

Due to the extraordinary heat wave that sent temperatures soaring to summer-like levels across the eastern two-thirds of the country, March was officially the warmest such month in history for the Lower 48 states, the National Climatic Data Center (NCDC) announced. The heat wave was unprecedented in its scope and magnitude for so early in the year, with many locations breaking longstanding records by up to 40 degrees Fahrenheit. The U.S. surface temperature record dates back to 1895.

The dramatic temperature increases that thawed the last ice age followed spikes in carbon dioxide levels in the air, a new study finds. Researchers say that further strengthens the scientific case explaining current man-made global warming. In the new study, scientists show the atmospheric concentration of that heat-trapping greenhouse gas jumped more than 40 percent. Then global temperatures went up about 6 degrees Fahrenheit. What is remarkable is that when the two are plotted they rise, plateau and rise again in a striking similar way with a slight lag. The warming over 6,000 years follows the greenhouse gas increase, just as scientific theory has long held.

By changing the temperature balance between the Arctic and mid-latitudes, rapid Arctic warming is altering the course of the jet stream, which steers weather systems from west to east around the hemisphere. The Arctic has been warming about twice as fast as the rest of the Northern Hemisphere, due to a combination of human emissions of greenhouse gases and unique feedbacks built into the Arctic climate system. The jet stream is becoming “wavier,” with steeper troughs and higher ridges. Weather systems are progressing more slowly, raising the chances for long-duration extreme events, like droughts, floods, and heat waves.

The world is close to reaching tipping points that will make it irreversibly hotter, making this decade critical in efforts to contain global warming, scientists warned. Scientific estimates differ but the world's temperature looks set to rise by six degrees Celsius by 2100 if greenhouse gas emissions are allowed to rise uncontrollably. As emissions grow, scientists say the world is close to reaching thresholds beyond which the effects on the global climate will be irreversible, such as the melting of polar ice sheets and loss of rainforests.

As the USA simmers through its hottest March on record —with more than 6,000 record high temperatures already set this month — a new study released Sunday shows that average global temperatures could climb 2.5 to 5.4 degrees by 2050 if greenhouse gas emissions continue unabated. The study findings are based on the results of 10,000 computer model simulations of future weather overseen by researchers at Oxford University in the United Kingdom.

Extreme weather events over the past decade have increased and were "very likely" caused by manmade global warming, a study in the journal Nature Climate Change said.Scientists at Germany's Potsdam Institute for Climate Research used physics, statistical analysis and computer simulations to link extreme rainfall and heat waves to global warming. The link between warming and storms was less clear."It is very likely that several of the unprecedented extremes of the past decade would not have occurred without anthropogenic global warming," said the study. The past decade was probably the warmest globally for at least a millennium. Last year was the eleventh hottest on record, the World Meteorological Organization said.

A severe drought in Mexico that has cost farmers more than a billion dollars in crop losses alone and set back the national cattle herd for years, is just a foretaste of the drier future facing Latin America's second largest economy. The overall cost to the economy is still being gauged but Mexico's drought-stung winter has been evolving for years and is expected to worsen as the effect of global climate change takes hold, according to the government.

According to some climate scientists, earlier-than-normal outbreaks of tornadoes, which typically peak in the spring, will become the norm as the planet warms.Whether climate change will also affect the frequency or severity of tornadoes, however, remains very much an open question.

A warm spell and a low-dipping jet stream are fueling the monster storms that are spawning tornadoes Friday across a wide swath of the country, weather experts said. Friday, the Storm Prediction Center has received 311 reports of severe weather, including 48 reported tornadoes and a few reported fatalities. This massive storm system also spawned deadly tornadoes on Leap Day, which raked Kansas, Nebraska, Illinois, Indiana, Missouri, Kentucky and Tennessee. As of Friday morning, the severe storm risk area covered an estimated 162 million people, or 56 percent of the United States, according to weather experts at the National Oceanic and Atmospheric Administration (NOAA). While the main tornado season runs from spring to early summer, this year's early outbreaks show that tornadoes can form under a variety of conditions and strike during fall and winter, too. This year's mild winter and warm start to meteorological spring has upped the risk of dangerous storms.

The world last year wasn't quite as warm as it has been for most of the past decade, government scientists said Thursday, but it continues a general trend of rising temperatures. The average global temperature was 57.9 degrees Fahrenheit, making 2011 the 11th hottest on record, the National Oceanic and Atmospheric Administration said. That's 0.9 degrees warmer than the 20th century average, officials said. In fact, it was hotter than every year last century except 1998. One reason 2011 was milder than recent years was the La Nina cooling of the central Pacific Ocean. La Ninas occur every few years and generally cause global temperatures to drop, but this was the warmest La Nina year on record.

Warmer summers in the far Northern Hemisphere are disrupting weather patterns and triggering more severe winter weather in the United States and Europe, a team of scientists say, in a finding that could improve long-range weather forecasts. Blizzards and extreme cold temperatures in the winters of 2009/10 and 2010/11 caused widespread travel chaos in parts of Europe and the United States. Judah Cohen, lead author of a study published in the journal Environmental Research Letters, and his team found there was a clear trend of strong warming in the Arctic from July to September. Existing predictions would also expect a warming trend during winter as well. But Cohen and his team found this was not the case for some regions.

Amounts of warming previously thought to be safe may instead trigger widespread melting of the world's ice sheets and other catastrophic impacts, scientists said Tuesday. "The dangerous level of global warming is less than what we thought a few years ago," said James Hansen, director of NASA Goddard Institute for Space Studies. "It was natural to think that a few degrees wasn't so bad.... (But) a target of two degrees is actually a prescription for long-term disaster."

Global carbon dioxide emissions from burning fossil fuels have increased by 49 per cent in the last two decades, according to researchers at the Tyndall Centre for Climate Change Research, University of East Anglia. Fossil fuel emissions increased by 5.9 per cent in 2010 and by 49 per cent since 1990 -- the reference year for the Kyoto protocol. On average, fossil fuel emissions have risen by 3.1 per cent each year between 2000 and 2010 -- three times the rate of increase during the 1990s. They are projected to continue to increase by 3.1 per cent in 2011.

Global warming has brought a "new normal" to the Arctic, with warmer air and ocean temperatures, thinner and less expansive summer sea ice, and greener vegetation in coastal regions abutting the open water. In addition, longer periods of open water during the annual sea-ice melt season is allowing the ocean to take up more carbon dioxide from the atmosphere, leading to seasonal bouts of ocean acidification in some areas.These broad observations, along with more-detailed looks at some 32 environmental indicators, appear in the National Oceanic and Atmospheric Administration's 2011 Arctic Report Card. The changes have wide implications, from opening new sources of offshore oil, gas, and minerals to speeding the release of heat-trapping methane into the atmosphere as permafrost melts.

The world is getting hotter, with 2011 one of the warmest years on record, and humans are to blame, a report by the World Meteorological Organization (WMO) said. "Global temperatures in 2011 are currently the tenth highest on record and are higher than any previous year with a La Nina event, which has a relative cooling influence," the WMO report said

The global output of heat-trapping carbon dioxide jumped by the biggest amount on record, the U.S. Department of Energy calculated, a sign of how feeble the world's efforts are at slowing man-made global warming. The new figures for 2010 mean that levels of greenhouse gases are higher than the worst case scenario outlined by climate experts just four years ago. Moreover the record high levels of greenhouse gases causing climate change will linger in the atmosphere for decades to come, even if the world manages to stop emissions output today, the United Nations' World Meteorological Organization said.

The International Energy Agency warned that the world is hurtling toward irreversible climate change and will lose the chance to limit warming if it doesn't take bold action in the next five years. The agency's chief economist, Fatih Birol, said this week that he's not optimistic that leaders are willing to make the necessary sacrifices.

Freakish weather disasters — from the sudden October snowstorm in the Northeast U.S. to the record floods in Thailand — are striking more often. And global warming is likely to spawn more similar weather extremes at a huge cost, says a draft summary of an international climate report obtained by The Associated Press. The final draft of the report from a panel of the world's top climate scientists paints a wild future for a world already weary of weather catastrophes costing billions of dollars. The report says costs will rise and perhaps some locations will become "increasingly marginal as places to live."

A prominent physicist and skeptic of global warming spent two years trying to find out if mainstream climate scientists were wrong. In the end, he determined they were right: Temperatures really are rising rapidly. The study of the world’s surface temperatures by Richard Muller was partially bankrolled by a foundation connected to global warming deniers. He pursued long-held skeptic theories in analyzing the data. He was spurred to action because of “Climategate,” a British scandal involving hacked emails of scientists. Yet he found that the land is 1.6 degrees warmer than in the 1950s, matching figures provided by the National Oceanic and Atmospheric Administration and NASA.

Global temperature rise could exceed "safe" levels of two degrees Celsius in some parts of the world in many of our lifetimes if greenhouse gas emissions continue to increase, two research papers published in the journal Nature warned.

This year, Texas led the nation in hot-car deaths; the drought caused higher food prices; high temperatures caused railroad tracks in North Texas to warp; the heat triggered asthma and allergy symptoms; and the heat caused foundation problems for homeowners. According to a new report from NOAA, this may well be the "new normal" for the state.

A cyclical drop in the sun's radiation can trigger unusually cold winters in parts of North America and Europe, scientists say, a finding that could improve long-range forecasts and help countries prepare for blizzards. Scientists have known for a long time that the sun has an 11-year cycle during which radiation measured by sunspots on the surface reaches a peak then falls. But pinning down a clear link to weather has proved harder. The researchers found that a reduction in ultraviolet (UV) radiation from the sun can affect high-altitude wind patterns in the Northern Hemisphere, triggering cold winters.

The Earth moves all by itself, but it is becoming increasingly clear that climate plays a role in when and how often. What happens on the surface can suppress quakes and eruptions - and trigger them. There are already signs of such effects in the world's northern regions, which are warming fastest. So seriously is the issue being taken that an upcoming special report on extreme events and disasters related to climate change, commissioned by the Intergovernmental Panel on Climate Change, will include a section on the relationship between changes in the climate and tectonic activity.

The mystery of Earth's missing heat may have been solved: it could lurk deep in oceans, temporarily masking the climate-warming effects of greenhouse gas emissions, researchers reported. Climate scientists have long wondered where this so-called missing heat was going, especially over the last decade, when greenhouse emissions kept increasing but world air temperatures did not rise correspondingly.The mystery of Earth's missing heat may have been solved: it could lurk deep in oceans, temporarily masking the climate-warming effects of greenhouse gas emissions, researchers reported.

Relying more on natural gas than on coal would not significantly slow down the effects of climate change, even though direct carbon dioxide emissions would be less, a new study has found. Burning coal emits far more climate-warming carbon dioxide than natural gas does, but it also releases lots of sulfates and other particles that block incoming sunlight and help cool the Earth, according to a study to be published in the peer-reviewed journal Climate Change Letters in October. Using more natural gas for fuel could also produce leaks of methane, a heat-trapping greenhouse gas more than 20 times more potent than carbon dioxide, study author Tom Wigley said in a statement.

Blizzards. Tornadoes. Floods. Record heat and drought, followed by wildfires. The first eight months of 2011 have brought strange and destructive weather to the United States.Climate experts point to global warming, meteorologists cite the influence of La Nina or natural variability, and, in the case of tornadoes hitting populated areas, many simply call the death and destruction bad luck. But given the variety and violence of both short-term weather events and longer-term effects like a Southwestern drought that has lasted years, more scientists say climate itself seems to be shifting and weather extremes will become more common.

Climate scientists point to the predictable and cumulative effects of climate change — both hot and cold — to account for much of the extreme weather, although the connection between tornadoes and climate is not clear. In any event, scientists caution that the future will hold greater temperature extremes, and for longer duration.

Two hundred million years ago, a mass extinction, often attributed to major volcanic activity, wiped out half of all marine life on Earth. But new research published in the journal Science suggests that the extinction was more likely to have been caused by the release of at least 12,000 gigatons of methane from the seafloor into the atmosphere. “There was a release of CO2 from volcanic eruptions that warmed up global temperatures and also the ocean,” said Dr. Micha Ruhl, of the University of Copenhagen, who added: “Methane is only stable under certain temperatures. If it gets warm, it is released.” The study could be foreshadowing the effect of climate change on Earth.

Persistent, scorching heat in the central and eastern regions of the United States shattered long-standing daily and monthly temperature records last month, making it the fourth warmest July on record nationally. The heat exacerbated drought conditions, resulting in the largest “exceptional” drought footprint in the 12-year history of the U.S. Drought Monitor. “Exceptional” is the most severe category of drought on the drought monitor scale. Drought conditions at several locations in the South region are not as long lived, but are as dry, or drier, than the historic droughts of the 1930s and 1950s.

The soil and the ocean are being weakened as buffers against global warming, in a vicious circle with long-term implications for the climate system, say two new investigations. If the seas and the land are less able to soak up or store greenhouse gases, more of these carbon emissions will enter the atmosphere, holding in even more heat from the sun. A study published in Nature says a gradual increase in atmospheric carbon dioxide (CO2) over the last half-century has accelerated the release of methane and nitrous oxide in the soil.

Smoke belching from Asia's rapidly growing economies is largely responsible for a halt in global warming in the decade after 1998 because of sulphur's cooling effect, even though greenhouse gas emissions soared, a U.S. study said. The paper raised the prospect of more rapid, pent-up climate change when emerging economies eventually crack down on pollution. World temperatures did not rise from 1998 to 2008, while manmade emissions of carbon dioxide from burning fossil fuel grew by nearly a third, various data show.

An irreversible climate "tipping point" could occur within the next 20 years as a result of the release of huge quantities of organic carbon locked away as frozen plant matter in the vast permafrost region of the Arctic, scientists have found. Billions of tons of frozen leaves and roots that have lain undisturbed for thousands of years in the permanently frozen ground of the northern hemisphere are thawing out, with potentially catastrophic implications for climate change, the researchers said. A study into the speed at which the permafrost is melting suggests that the tipping point will occur between 2020 and 2030 and will mark the point at which the Arctic turns from being a net "sink" for carbon dioxide into an overall source that will accelerate global warming.

Climate models of the current generation, as used in the latest assessment of the Intergovernmental Panel on Climate Change (IPCC), have not proved their ability to simulate abrupt change when a critical threshold is crossed. In two well-documented examples of past rapid climate change, the models did not adequately capture the basic climate configuration before abrupt change ensued, and in the remaining two examples, to initiate abrupt change the models needed external nudging that is up to ten times stronger than reconstructed. The models seem to be too stable.

The world’s climate is not only continuing to warm, it’s adding heat-trapping greenhouse gases even faster than in the past, researchers said. The global temperature has been warmer than the 20th century average every month for more than 25 years, they said at a teleconference. Carbon dioxide increased by 2.60 parts per million in the atmosphere in 2010, which is more than the average annual increase seen from 1980-2010.

For government scientists usually cautious about going out on a limb, a "special report" issued Wednesday minced few words: Last April saw an unprecedented onslaught of extreme tornadoes, flooding, drought and wildfire, they concluded. "While similar extremes have occurred throughout modern American history," the report by experts at the National Climatic Data Center stated, "never before have they occurred in a single month."

In the study to be published later this month in the journal Climate Change, Stanford University researchers conclude that many tropical regions in Africa, Asia and South America could see "the permanent emergence of unprecedented summer heat" in the next two decades. The middle latitudes of Europe, China and North America, including the United States, are likely to undergo extreme temperature shifts within 60 years, the researchers found.

Global warming is not directly to blame for last summer's deadly — and extraordinary — heat wave in Russia, researchers said in a report Wednesday that came with a climate warning. "We may be on the cusp of a period in which the probability of such events increases rapidly, due primarily to the influence of projected increases in greenhouse gas concentrations," said the team of scientists from the U.S. National Oceanic and Atmospheric Administration.

Ancient megadroughts that lasted thousands of years in what is now the American Southwest could offer a preview of a climate changed by modern greenhouse gas emissions, researchers reported. The scientists found these persistent dry periods were different from even the most severe decades-long modern droughts, including the 1930s "Dust Bowl." And they determined that these millennial droughts occurred at times when Earth's mean annual temperature was similar to or slightly higher than what it is now.

Extreme rainstorms and snowfalls have grown substantially stronger, two studies suggest, with scientists for the first time finding the telltale fingerprints of man-made global warming on downpours that often cause deadly flooding. The two studies — reported in the peer-reviewed journal Nature and packaged on its cover as "The Human Factor" — link extreme precipitation to increases in greenhouse gases more than ever before.

New government figures for the global climate show that 2010 was the wettest year in the historical record, and it tied 2005 as the hottest year since record-keeping began in 1880. The new figures confirm that 2010 will go down as one of the more remarkable years in the annals of climatology. It featured prodigious snowstorms that broke seasonal records in the United States and Europe; a record-shattering summer heat wave that scorched Russia; strong floods that drove people from their homes in places like Pakistan, Australia, California and Tennessee; a severe die-off of coral reefs; and a continuation in the global trend of a warming climate.

Climate change has likely intensified the monsoon rains that have triggered record floods in Australia's Queensland state, scientists said, with several months of heavy rain and storms still to come. "I think people will end up concluding that at least some of the intensity of the monsoon in Queensland can be attributed to climate change," said Matthew England of the Climate Change Research Center at the University of New South Wales in Sydney. "The waters off Australia are the warmest ever measured and those waters provide moisture to the atmosphere for the Queensland and northern Australia monsoon," he told Reuters.

Scientists have uncovered what appears to be a further dramatic increase in the leakage of methane gas that is seeping from the Arctic seabed. Methane is about 20 times more potent than CO2 in trapping solar heat. "Methane release from the East Siberian Shelf is underway and it looks stronger than it was supposed [to be]," said Prof. Igor Semiletov of the University of Alaska. Methane seepage recorded last summer was already the highest ever measured in the Arctic Ocean.

The cold spell Ireland and the rest of northern Europe has been experiencing may, paradoxically, be the result of global warming, rather than evidence it is not happening, according to the most recent scientific research. The Journal of Geophysical Research suggested a link between diminishing levels of sea ice in the Arctic and an increased probability of harsh winters across Europe, saying these “do not conflict the global warming picture, but rather supplement it”.

World temperatures could soar by 4 degrees Celsius (7.2 degrees Fahrenheit) by the 2060s in the worst case of global climate change and require an annual investment of $270 billion just to contain rising sea levels, studies suggested. Such a rapid rise, within the lifetimes of many young people today, is double the 2 degrees C (3.6 degrees Fahrenheit) ceiling set by 140 governments at a U.N. climate summit in Copenhagen last year and would disrupt food and water supplies in many parts of the globe.

The U.N. weather agency has found that greenhouse gas levels in the atmosphere reached record levels in 2009. The World Meteorological Organization says concentrations of carbon dioxide rose in 2009 by 1.6 parts per million, to 386.8 parts per million. The preindustrial carbon dioxide average was about 280 parts per million. The higher the concentration of greenhouse gases, the more heat is trapped in the atmosphere.

Gas locked inside Siberia's frozen soil and under its lakes has been seeping out since the end of the last ice age 10,000 years ago. But in the past few decades, as the Earth has warmed, the icy ground has begun thawing more rapidly, accelerating at a perilous rate the release of methane, a greenhouse gas 23 times more powerful than carbon dioxide.

Global emissions of planet-warming carbon dioxide are on track to hit a record in 2010, a leading annual study said , driven largely by booming economies in China and India and their reliance on coal. The Global Carbon Project, a consortium of international research bodies, also said annual emissions dipped 1.3 percent in 2009 from 2008 because of the global financial crisis. But the fall was less than half the decrease estimated a year ago.

Climate change could lead to colder winters in northern regions, according to a study by the Potsdam Institute for Climate Impact Research. Vladimir Petoukhov, lead author of the study, said a shrinking of sea ice in the eastern Arctic causes some regional warming of lower air levels and may lead to anomalies in atmospheric airstreams, triggering an overall cooling of the northern continents. "These anomalies could triple the probability of cold winter extremes in Europe and northern Asia," he said. "Recent severe winters like last year's or the one of 2005/06 do not conflict with the global warming picture but rather supplement it."

Not only is Earth's surface warming, but the troposphere -- the lowest level of the atmosphere, where weather occurs -- is heating up too, U.S. and British meteorologists reported on Monday. The scientists found that warming in this key atmospheric layer was occurring, just as many researchers expected it would as more greenhouse gases built up and trapped heat close to the Earth. This study aims to put to rest a controversy that began 20 years ago, when a 1990 scientific report based on satellite observations raised questions about whether the troposphere was warming, even as Earth's surface temperatures climbed.

A new study has shed light on the sun's impact on the Earth's climate, confounding current thinking about solar cycles and how they influence temperatures on Earth Previously scientists had thought that radiation reaching the Earth rises and falls in line with the Sun's activity, which during the 11-year solar cycle goes though periods of low and high activity But research by Imperial College, London and the University of Colorado in the U.S. examining solar radiation levels from 2004 to 2007 -- a period of declining solar activity -- revealed that levels of visible radiation reaching the Earth actually increased during the period.

Researchers who set out to create a baseline for future research on water cycle trends on Monday reported an alarming discovery: 18 percent more water was fed into the oceans from rivers and melting polar ice sheets in 2006 than in 1994. The experts suspect that the evaporation and precipitation cycle of water is accelerating dangerously because of greenhouse gas-fueled higher temperatures. That, in turn, would trigger more severe monsoons and hurricanes.

Scientists from around the world are providing even more evidence of global warming, one day after President Barack Obama renewed his call for climate legislation. "A comprehensive review of key climate indicators confirms the world is warming and the past decade was the warmest on record," the annual State of the Climate report declares. "What this data is doing is, it is screaming that the world is warming," concluded one author of the study.

Global land and ocean surface temperatures in the first half of 2010 were the warmest January-June on record, the federal climate service reported. January-June temperatures averaged 57.5 degrees Fahrenheit — 1.22 degrees F above the 20th Century average, according to the National Climatic Data Center. Its records go back to 1880. That broke the previous record of 1.19 degrees F above average set in 1998. 2010 has also surpassed 1998 for the most "warmest months" in any calendar year, the center stated.

The National Academy of Sciences wants to put the United States on a low-carbon diet. That is the underlying message of a hotly anticipated trio of reports requested by Congress and released today. In them, the academy describes an "urgent need" for the nation to trim its greenhouse gas emissions.

The combined global land and ocean surface temperature was the warmest on record for both April and for the period from January-April, according to NOAA. Additionally, last month’s average ocean surface temperature was the warmest on record for any April, and the global land surface temperature was the third warmest on record.

Climate change could spark more "hazardous" geological events such as volcanoes, earthquakes and landslides, scientists warned.In papers published by the Royal Society, researchers warned that melting ice, sea level rises and even increasingly heavy storms and rainfall - predicted consequences of rising temperatures - could affect the Earth's crust. Even small changes in the environment could trigger activity such as earthquakes and tsunamis.

Brace yourself for more winters like the last one, northern Europe. Freezing conditions could become more likely: winter temperatures may even plummet to depths last seen at the end of the 17th century, a time known as the Little Ice Age. That's the message from a new study that identifies a compelling link between solar activity and winter temperatures in northern Europe. The research finds that low solar activity promotes the formation of giant kinks in the jet stream. These kinks can block warm westerly winds from reaching Europe, while allowing in winds from Arctic Siberia. When this happens in winter, northern Europe freezes, even though other, comparable regions of the globe may be experiencing unusually mild conditions.

The Northeast is seeing more frequent "extreme precipitation events" in line with global warming predictions, a study shows, including storms like the recent fierce rains whose floodwaters swallowed neighborhoods and businesses across New England. The study does not link last week's devastating floods to its research but examined 60 years' worth of National Weather Service rainfall records in nine Northeastern states and found that storms that produce an inch or more of rain in a day — a threshold the recent storm far surpassed — are coming more frequently.

The first of several British investigations into the e-mails leaked from one of the world's leading climate research centers has largely vindicated the scientists involved. The House of Commons' Committee said Wednesday that they'd seen no evidence to support charges that the University of East Anglia's Climatic Research Unit or its director, Phil Jones, had tampered with data or perverted the peer review process to exaggerate the threat of global warming - two of the most serious criticisms levied against the climatologist and his colleagues. The committee concluded that "the scientific reputation of Professor Jones and CRU remains intact," adding that nothing in the more than 1,000 stolen e-mails, or the controversy kicked up by their publication, challenged scientific consensus that "global warming is happening and that it is induced by human activity."

Global warming has neither stopped nor slowed in the past decade, according to a draft analysis of temperature data by NASA's Goddard Institute for Space Studies. The analysis, led by senior scientist Jim Hansen, attempts to debunk popular belief that the planet is cooling. It finds that global temperatures over the past decade have "continued to rise rapidly," despite large year-to-year fluctuations associated with the tropical El Niño-La Niña cycles. The analysis also predicts, assuming current El Niño conditions hold, that 2010 will go down in history as the hottest year on record despite an unusually snowy winter in the Northern Hemisphere.

The sun contributes almost all of the energy into our atmosphere through electromagnetic radiation, so when our nearest star reduces its output, one would think that our atmosphere would cool down (or, at least, wouldn't heat up).

But a new study published in the journal Geophysical Research Letters says that even if the sun commenced a very long period of low activity, it cannot put the brakes on the relentless rise of global temperatures caused by greenhouse gases.

The case for man-made global warming is even stronger than the Intergovernmental Panel on Climate Change maintained in its official assessments, according to the first scientific review published since December’s Copenhagen conference and subsequent attacks on the IPCC’s credibility. An international research team led by the UK Met Office spent the past year analysing more than 100 recent scientific papers to update the last IPCC assessment, released in 2007.

The year 2009 was tied for the second warmest year in the modern record, according to a new analysis of global surface temperature from the National Aeronautics and Space Administration. Conducted by NASA's Goddard Institute for Space Studies in New York City, the analysis also shows that in the Southern Hemisphere, 2009 was the warmest year since modern records began in 1880. January 2000 to December 2009 was the warmest decade on record. Throughout the last three decades, the GISS surface temperature record shows an upward trend of about 0.2°C (0.36°F) per decade.

A new study helps explain why the planet didn't warm up dramatically over the course of the past decade, even though the gases that cause global warming increased dramatically. It turns out that starting in the year 2000, a narrow layer of the stratosphere dried out quite rapidly. And water in the atmosphere traps heat, like glass in a greenhouse. So less stratospheric water means less warming.

The 2000-2009 decade was the warmest on record, easily surpassing the previous hottest decade — the 1990s — researchers saidin a report providing fresh evidence that the planet may be warming at a potentially disastrous rate.In 2009, global surface temperatures were 1.01 degree above average, which tied the year for the fifth warmest year on record, the National Climatic Data Center said. That helped push the 2000-2009 decade to 0.96 degree above normal, which the agency said "shattered" the 1990s record value of 0.65 degree above normal.

A section of the Arctic Ocean seafloor that holds vast stores of frozen methane is showing signs of instability and widespread venting of the powerful greenhouse gas, according to the findings of an international research team.

The research results, published in the March 5 edition of the journal Science, show that the permafrost under the East Siberian Arctic Shelf, long thought to be an impermeable barrier sealing in methane, is perforated and is leaking large amounts of methane into the atmosphere. Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming.

Carbon dioxide concentrations in the early Pliocene, about 5 million years ago, were likely between 365 and 415 ppm. During that period, palm trees grew in Antarctica and alligators swam in the Arctic. We're already well within that range.

It may not seem so in many places today, today, but North America and Eurasia's snow cover has shrunk, according to study of more than 40 years of weather satellite-based snow cover maps. The discovery of a sharp decline in late winter and early spring snow cover starting in the 1980s until 1990 was revealed after researchers made overdue adjustments to decades of daily snow cover maps.

Global warming will resume its upward climb again next year, the UK Met Office predicted yesterday.The "central estimate" of their forecast is that the global average surface temperature for 2010 will be 0.58 degrees C above the long-term average for 1961-1990 (which is 14 degrees C), compared to the average for 1998, which was 0.52 degrees above.

Global warming is happening faster than expected and at worst could raise sea levels by up to 2 meters (6-1/2 ft) by 2100, a group of scientists said.

In what they called a "Copenhagen Diagnosis," updating findings in a broader 2007 U.N. climate report, 26 experts urged action to cap rising world greenhouse gas emissions by 2015 or 2020 to avoid the worst impacts of climate change. "Climate change is accelerating beyond expectations," a joint statement said, pointing to factors including a retreat of Arctic sea ice in summer and melting of ice sheets on Greenland and Antarctica.

Levels of most greenhouse gases continue to increase. In 2008, global concentrations of carbon dioxide, methane and nitrous oxide, which are the main long-lived greenhouse gases in the atmosphere, have reached the highest levels recorded since pre-industrial times. Since 1990, the overall increase in radiative forcing caused by all long-lived greenhouse gases is 26% and the increase was 1.3% from 2007 to 2008. These latest figures, published today in the World Meteorological Organization’s (WMO) 2008 Greenhouse Gas Bulletin, confirm the continued trend of rising atmospheric burdens of greenhouse gases since 1750.

Average global temperatures are on course to rise by up to 6C without urgent action to curb CO2 emissions, the lead author of a new analysis says.

Emissions rose by 29% between 2000 and 2008, says the Global Carbon Project. All of that growth came in developing countries, but a quarter of it came through production of goods for consumption in industrialised nations.

New research shows that daily record high temperatures across the continental U.S. occurred twice as often as record lows over the last decade. "Climate change is making itself felt in terms of day-to-day weather," a researcher at the National Center for Atmospheric Research said in a statement announcing the research. "The ways these records are being broken show how our climate is already shifting."

Last week we proposed a bet against the “pause in global warming” forecast in Nature by Keenlyside et al. and we promised to present our scientific case later – so here it is. This is why we do not think that the forecast is robust:

We are on the verge of pushing nature into a state of instability like nothing humanity has seen before, according to a study published in the journal Nature. The study found that we may have already crossed several tipping points.

The world faces record-breaking temperatures as the sun's activity increases, leading the planet to heat up significantly faster than scientists had predicted for the next five years. The new study is the first to assess the combined impact on global temperature of four factors: human influences such as CO2 and aerosol emissions; heating from the sun; volcanic activity and the El Nino southern oscillation.

Climate researchers have long viewed clouds' reaction to greenhouse warming as the key to understanding the world's climatic fate. As rising carbon dioxide strengthens the greenhouse, will some clouds thicken and spread, shading the planet and tempering the warming? Or will they thin and shrink, letting in more sunshine to amplify the warming? The first reliable analysis of cloud behavior over past decades suggests -- but falls short of proving -- that clouds are strongly amplifying the warming.

Man-made climate change is already lifting temperatures, increasing rainfall, and raising sea levels around the United States -- and its effects are on track to get much worse in the coming century, according to a report released by federal scientists.

The depleted ozone layer is wreaking havoc with winds over Antarctica and the Southern Ocean, according to a new study. Shifting air currents are preventing waters from soaking up the man-made greenhouse gas carbon dioxide (CO2), and simultaneously worsening the effects of ocean acidification.

World carbon emissions must start to decline in only six years if humanity is to stand a chance of preventing dangerous global warming, a group of 20 Nobel prize-winning scientists, economists and writers declared.

This paper concludes that it is increasingly unlikely any global agreement will deliver the radical reversal in emission trends required for stabilization at 450 ppmv carbon dioxide equivalent (CO2e). Similarly, the current framing of climate change cannot be reconciled with the rates of mitigation necessary to stabilize at 550 ppmv CO2e and even an optimistic interpretation suggests stabilization much below 650 ppmv CO2e is improbable .

The world will overshoot its long-term target on greenhouse gas emissions within two decades. A study has found that the average global temperature will rise above the threshold that could cause dangerous climate change during that time.

Wildfires Seen Intensifying Climate Change In a vicious cycle made worse by humans, scientists now believe fires spur climate change, which in turn makes blazes bigger, more frequent and more damaging to the environment.

Global warming is likely to overshoot a 2 degrees Celsius (3.6 F) rise seen by many as a trigger for "dangerous" change, a Reuters poll of scientists showed. Nine of 11 experts, who were among authors of the final summary by the U.N.'s Intergovernmental Panel on Climate Change in 2007 (IPCC), also said the evidence that mankind was to blame for climate change had grown stronger in the past two years.

Human-produced carbon dioxide in the atmosphere has been increasing exponentially for at least the last 50 years. Using measurements of atmospheric CO2, a team of researchers determined that humanity's contribution of the greenhouse gas has been growing at a steady 2.3 percent since recording began in 1958. At that rate, CO2 doubles every 30 years.

Global Crisis Seen Arriving by 2030 Growing world population -- exacerbated by climate change -- will cause a "perfect storm" of food, energy and water shortages by 2030, the UK government chief scientist has warned.

Climate change will wipe out most life on Earth by the end of this century and mankind is too late to avert catastrophe, a leading British climate scientist said. James Lovelock, 89, famous for his Gaia theory of the Earth being a kind of living organism, said higher temperatures will turn parts of the world into desert and raise sea levels, flooding other regions. The population of this hot, barren world could shrink from about seven billion to one billion by 2100 as people compete for ever-scarcer resources.

Arctic Thaw Portends Huge Methane Releases As permafrost thaws in the Arctic, huge pockets of methane -- a potent greenhouse gas -- could be released into the atmosphere. Experts are only beginning to understand how disastrous that could be.

The pace of global warming is likely to be much faster than recent predictions, because industrial greenhouse gas emissions have increased more quickly than expected and higher temperatures are triggering self-reinforcing feedback mechanisms in global ecosystems, scientists said.

The Earth's seasons have shifted back in the calendar year, with the hottest and coldest days of the years now occurring almost two days earlier, a new study finds. This shift could be the work of global warming.

Greenhouse gas levels currently expected by mid-century will produce devastating long-term droughts and a sea-level rise that will persist for 1,000 years regardless of how well the world curbs future emissions of carbon dioxide, an international team of scientists reported yesterday.

Rapid Climate Change Could Impact US "within decades" The US could suffer the effects of abrupt climate changes within decades -- sooner than some previously thought -- says a new government report. It contends that seas could rise rapidly if melting of polar ice continues to outrun recent projections, and that an ongoing drought in the U.S. west could be the start of permanent drying for the region.

IPCC Chair Sees Worsening Climate Impacts An extra billion people will face water shortage, cereal production in developing countries will drop and coastal regions will face more damage from floods and storms because of delay in combating climate change, says Martin Parry, former co-chair of the IPCC.

The latest analysis of data from the WMO-GAW Global Greenhouse Gas Monitoring Network shows that the globally averaged mixing ratios of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N20) have reached new highs in 2007, with CO2 at 383.1 ppm, CH4 at 1789 ppb, and N20 at 320.9 ppb. These values are higher than pre-industrial times (before 1750) by 37 percent.

Drinking Water Shortages Loom for Half the World's People by 2080Half the world's population could face a shortage of clean water by 2080 because of climate change, experts warned. Wong Poh Poh, a professor at the National University of Singapore, told a regional conference that global warming was disrupting water flow patterns and increasing the severity of floods, droughts and storms -- all of which reduce the availability of drinking water.

Asian Smog Masks Warming Impacts: UN A three-kilometer thick cloud of brown soot and other pollutants hanging over Asia is darkening cities, killing thousands and damaging crops but may be holding off the worst effects of global warming, the U.N. said. This atmospheric brown cloud "has masked the true nature of global warming on our planet," United Nations Environment Program head Achim Steiner said.

Atmosphere is Ripe for Climate Disaster Now If climate disasters are to be averted, atmospheric carbon dioxide (CO2) must be reduced below the levels that already exist today, according to a study by of 10 scientists from the United States. The authors assert that to maintain a planet similar to that on which civilization developed, an optimum CO2 level would be less than 350 ppm -- a dramatic change from most previous studies, which suggested a danger level for CO2 is likely to be 450 ppm or higher.

Scientists have found the first increase in methane levels this century -- by about 28 million tonnes since mid-2006 -- was in part due to release of gas in and near the Arctic.

Sudden Methane Rise Puzzles Scientists Levels of climate-warming methane -- a greenhouse gas 25 times as potent as carbon dioxide -- rose abruptly in Earth's atmosphere last year, and scientists who reported the change don't know why it occurred. Methane has more than doubled in the atmosphere since pre-industrial times, but stayed largely stable over the last decade or so before rising in 2007.

Climate change is happening much faster than the world's best scientists predicted and will wreak havoc unless action is taken on a global scale, a new report warns.

Higher Inland Temperatures Cool Coastal Areas A team of scientists has found that as temperatures rise in California, so do pressure differences that control cool Pacific winds. That means higher temperatures inland create lower ones at the coast.

Scientists claim to have discovered evidence for large releases of methane into the atmosphere from frozen seabed stores off the northern coast of Siberia. A large injection of the gas - which is 21 times more potent as an atmospheric heat trap than carbon dioxide - has long been cited by climate scientists as the potential trigger for runaway global warming. But some experts have expressed caution at the claims.

Scientists may have to clean the atmosphere of all man-made carbon dioxide to prevent the worst impacts of global warming, one of Europe's most senior climate scientists has warned. Professor John Schellnhuber said only a return to pre-industrial levels of CO2 would be enough to guarantee a safe future for the planet, addingcurrent political targets to slow the growth in emissions and stabilise carbon levels were insufficient.

The strongest tropical storms are becoming even stronger as the world's oceans warm, scientists have confirmed. Analysis of satellite data shows that in the last 25 years, strong cyclones, hurricanes and typhoons have become more frequent in most of the tropics.

Researchers confirm that surface temperatures in the Northern Hemisphere were warmer over the last 10 years than any time during the last 1300 years, and, if the climate scientists include the somewhat controversial data derived from tree-ring records, the warming is anomalous for at least 1700 years.

Warming Climate Intensifies RainstormsUS and British researchers have confirmed the link between warmer climate and an increase in powerful rainstorms, according to a study that underscores one of the challenges of global warming. The researchers even found that the increase of extreme rainfall was higher than what has been predicted in current computer models, according to the study published in the journal Science.

The UK should take active steps to prepare for dangerous climate change of perhaps 4C according to Robert Watson, former Clinton science adviser and former chief scientist at the World Bank.

Scientists Astounded by Speed of Prehistoric Deep Freeze A drastic cooling of the climate in western Europe happened exactly 12,679 years ago, apparently after a shift to icy winds over the Atlantic, scientists said, giving a hint of how abruptly the climate can change. The study, of pollens, minerals and other matter deposited in annual layers at the bottom of Lake Meerfelder Maar in Germany, pinpointed an abrupt change in sediments consistent with a sudden chill over just one year.

"More warming is already "in-the-pipeline," delayed only by the great inertia of the world ocean. And climate is nearing dangerous tipping points. Elements of a "perfect storm", a global cataclysm, are assembled."

Scientists Amazed By Speed of Ancient Climate "Snaps" The Northern Hemisphere briefly emerged from the last ice age some 14,700 years ago with a 22-degree-Fahrenheit spike in just 50 years, then plunged back into icy conditions before abruptly warming again about 11,700 years ago. Massive "reorganizations" of atmospheric circulation coincided with each temperature spurt, with each reorganization taking just one or two years, according to a new study.

As greenhouse-gas emissions rise, North America is likely to experience more droughts and excessive heat in some regions even as intense downpours and hurricanes pound others more often, according to a report issued yesterday by the U.S. Climate Change Science Program.

A US-British team of climate scientists has now found a surprisingly simple explanation for the puzzling drop in the rise of global temperatures between the 1940s and early 1970s -- a difference in the way British and US ships' crews measured the sea surface temperatures.

Report Details Breadth of Current US Climate Impacts The rise in concentrations of carbon dioxide in the atmosphere from human activities is influencing climate patterns and vegetation across the United States and will significantly disrupt water supplies, agriculture, forestry and ecosystems for decades, according to a new federal report.

Scientists have warned that "reactive nitrogen" is accumulating on the planet which is linked with the greenhouse effect, smog, haze, acid rain, coastal "dead zones" and ozone depletion.

GHG Levels Unseen in 800,000 Years Greenhouse gases are at higher levels in the atmosphere than at any time in at least 800,000 years, according to a study of Antarctic ice that extends evidence that mankind is disrupting the climate.

The Earth's temperature may stay roughly the same for a decade, as natural climate cycles enter a cooling phase, scientists have predicted. But, they add, temperatures will again be rising quickly by about 2020.

Humanity today, collectively, must face the uncomfortable fact that industrial civilization itself has become the principal driver of global climate. If we stay our present course, using fossil fuels to feed a growing appetite for energy-intensive life styles, we will soon leave the climate of the Holocene, the world of prior human history. The eventual response to doubling preindustrial atmospheric CO2 likely would be a nearly ice-free planet.

Scientists have put forward several proposals to reduce the amount of sunlight that reaches the planet's surface, including the use of light-reflecting sulphate particles in the atmosphere and putting mirrors in orbit around the planet. But a

dding sulfur to the atmosphere would spark chemical reactions leading to the liberation of chlorine, a compound known to destroy ozone, the team reports online today in Science

The jet stream -- America's stormy weather maker -- is creeping northward and weakening, new research shows. That potentially means less rain in the already dry South and Southwest and more storms in the North.

The task of cutting greenhouse gas emissions enough to avert a dangerous rise in global temperatures may be far more difficult than previous research suggested, say scientists who have just published studies indicating that it would require the world to cease carbon emissions altogether within a matter of decades.

Warmer Autumns Add to Carbon Burden An international study investigating the carbon sink capacity of northern terrestrial ecosystems discovered that the duration of the net carbon uptake period (CUP) has on average decreased due to warmer autumn temperatures.

Scientists Declare 350 ppm a "Safe Level" of CO2 The concentration of carbon in the atmosphere is now about 380 parts per million and increasing by 2 parts per million each year. To stabilize Earth's climate, the concentration needs to fall to at least 350 parts per million.

The global annual temperature -- for combined land and ocean surfaces -- for 2007 is expected to be near 58.0 F -- and would be the fifth warmest since records began in 1880. Some of the largest and most widespread warm anomalies occurred from eastern Europe to central Asia.

Sir David King and John Schellnhuber, science advisors to the British and German governments, have told BBC News it is unlikely that levels of greenhouse gases can be kept low enough to avoid a projected temperature rise of 2C (3.6F).

IPCC: Earth Faces Abrupt, Irreversible ChangesThe Earth is hurtling toward a warmer age at a quickening pace, a Nobel-winning U.N. scientific panel said in a landmark report Saturday, warning of inevitable human suffering and the threat of species extinction.

Humanity is changing Earth's climate so fast and devouring resources so voraciously that it is poised to bequeath a ravaged planet to future generations, the UN warned in its most comprehensive survey of the environment. The report by UNEP says world leaders must propel the environment "to the core of decision-making" to tackle a daily worsening crisis.

Carbon dioxide (CO2) levels in the atmosphere have risen 35% faster than expected since 2000, says a study.International scientists found that inefficiency in the use of fossil fuels increased levels of CO2 by 17%. The other 18% came from a decline in the natural ability of land and oceans to soak up CO2 from the atmosphere.

Human activity is behind the rising levels of water vapour in the lower atmosphere over the past few decades, climatologists have concluded. The rises in humidity could affect patterns of extreme storms, they warn.

Marine Fossils Confirm CO2 Role in WarmingScientists have devised a new way to study Earth's past climate by analyzing the chemical composition of ancient marine fossils. The first tests support the view that atmospheric CO2 has contributed to dramatic climate variations in the past, and strengthen projections that human CO2 emissions could cause global warming.

Flannery: Danger Point Arrived Ahead of ScheduleThe global economic boom has accelerated greenhouse gas emissions to a dangerous threshold not expected for a decade and could potentially cause irreversible climate change, said one of Australia's leading scientists. Tim Flannery said a UN international climate change report due in November will show that greenhouse gases have already reached a dangerous level.

Pachauri Hints at Lowering 2-Degree Goal Governments may need to step up the fight against global warming to a level beyond even the toughest existing goals to help safeguard the planet, the head of the U.N. climate panel said.

A rise of two degrees centigrade in global temperatures -- the point considered to be the threshold for catastrophic climate change -- is now "very unlikely" to be avoided, the world's leading climate scientists said yesterday. The IPCC study added: The effects of climate change will be felt sooner than scientists realized and the world must learn to live with the effects.

The emerging story of a global climate shift a third of a billion years ago seems to be a prequel to what climate scientists expect from the current trend in global warming. Models

show that melting large to moderately-sized high latitude ice sheets resulted in a reversal of tropical trade winds and big expansions of low-latitude desert areas into what had been warm temperate forests.

As the world warms, the US will face more severe thunderstorms with deadly lightning, damaging hail and the potential for tornadoes, a trailblazing study by NASA scientists suggests. While other research has warned of broad weather changes on a large scale -- like more extreme hurricanes and droughts -- the new study predicts even smaller events like thunderstorms will be more dangerous because of global warming.

Greenhouse gases likely accounted for more than half of the widespread warmth across the continental United States last year, according to a new study by four scientists at NOAA's Earth System Research Lab in Boulder, Colo. Last year's average temperature was the second highest since record-keeping began in 1895. The team found that it was very unlikely that the 2006 El Niño played any role, though other natural factors likely contributed to the unusual warmth.

Residual CO2 Has Much Longer LifetimeThe fossil fuels we burn today may leave an atmospheric "hangover" lasting hundreds of thousands of years, which may cause enough residual warming to prevent the onset of the next ice age. The IPCC describes carbon dioxide as having a lifetime in the atmosphere of between five and 200 years before it is ultimately absorbed by the oceans. In fact, as much as one-tenth of the CO2 will linger in the air for at least 100,000 years, and perhaps much longer,

A controversial theory proposes mimicking volcanoes to fight global warming. But throwing sulfur particles into the sky may do more harm than good, a new study says. As well as cooling the planet, the sulfur particles would reduce rainfall and cause serious global drought, a new study says.

The haze of pollution that blankets southern Asia is accelerating the loss of Himalayan glaciers, bequeathing an incalculable bill to China, India and other countries whose rivers flow from this source, scientists warned.

Scientists: GHGs Behind Record British Downpours It's official: the heavier rainfall in Britain is being caused by climate change, a major new scientific study will reveal this week, as the country reels from summer downpours of unprecedented ferocity. More intense rainstorms across parts of the northern hemisphere are being generated by man-made global warming, the study has established for the first time ­-- an effect which has long been predicted but never before proved.

The level of 'dangerous interference' "is much lower than has commonly been assumed. If we have not already passed the dangerous level, the energy infrastructure in place ensures that we will pass it within several decades."

Global warming is accelerating three times more quickly than feared, a series of startling, authoritative studies has revealed. Emissions of carbon dioxide have been rising at three times the rate in the 1990s. The Arctic ice cap is melting three times as fast - and the seas are rising twice as rapidly - as had been predicted.

It used to be that climate scientists worried about how to make the public care about changes that might not happen for a century. Today they have a bigger problem: some of the changes arent waiting around that long.

"Danger Point" Looms for Humanity -- NASA Human-made greenhouse gases have brought the Earth's climate close to critical tipping points, with potentially dangerous consequences for the planet. The warming of 0.6ºC in the past 30 years has been driven mainly by greenhouse gases, and only moderate additional climate forcing is likely to set in motion disintegration of the West Antarctic ice sheet and Arctic sea ice.

Climate change change may have passed a key tipping point that could mean temperatures rising more quickly than predicted. A surge of carbon dioxide levels in the atmosphere in recent years is due to more greenhouse gas escaping from trees, plants and soils. Global warming was making vegetation less able to absorb the carbon pollution pumped out by human activity.

Scientists: Capacity of Earth's Sinks is OverestimatedWhile the continents and oceans have absorbed much of the carbon dioxide that humanity has pumped into the atmosphere so far, they won't be able to keep up with the expected rise in greenhouse-gas emissions over the next several decades. Indeed, some recent studies suggest that current scientific estimates about natural absorption are too optimistic.

Lead author James Hansen, NASA Goddard Institute for Space Studies, New York, concludes: "If global emissions of carbon dioxide continue to rise at the rate of the past decade, this research shows that there will be disastrous effects, including increasingly rapid sea level rise, increased frequency of droughts and floods, and increased stress on wildlife and plants due to rapidly shifting climate zones."

Chicago and Los Angeles will likely face increasing heat waves. Severe storm surges could hit New York and Boston. And cities that rely on melting snow for water may run into serious shortages. These findings about North America were released in the report finished last week by the Intergovernmental Panel on Climate Change.

An international conference of global warming scientists approved a report warning of dire threats to the Earth and to mankind from increased hunger in Africa and Asia to the extinctions of species unless the world adapts to climate change and halts its progress.

Some sections of a grim scientific assessment of the impact of global warming on human, animal and plant life issued in Brussels yesterday were softened at the insistence of officials from China and the United States, participants in the negotiations said. The delegates removed parts of key charts highlighting devastating effects of climate change that kick in with every rise of 1.8 degrees Fahrenheit The charts have been called a "highway to extinction" because they show that with every degree of warming, the condition of much of the world worsens -- with starvation, floods and the disappearance of species.

The world's richest countries, which have contributed by far the most to the atmospheric changes linked to global warming, are already spending billions of dollars to limit their own risks from its worst consequences, like drought and rising seas. But they are spending just tens of millions of dollars on ways to limit climate and coastal hazards in the world's most vulnerable regions -- most of them close to the equator and overwhelmingly poor.

New calculations show that sensitivity of Earth's climate to changes in the greenhouse gas carbon dioxide has been consistent for the last 420 million years -- with each doubling of CO2 generating a temperature increase of 3* C.

The US Southwest has been warming for nearly 30 years. And the region is in the midst of an eight-year drought. What has convinced many scientists that the current spate of higher temperatures is not just another natural swing in the weather has been the near collapse of the sky islands and other high, formerly green havens that poke above the desert.

Scientific American: IPCC Understates Coming ChangesThe IPCC summary describes the existence of global warming as "unequivocal" but leaves out a reference to an accelerated trend in this warming. By excluding statements that provoked disagreement and adhering strictly to data published in peer-reviewed journals, the IPCC has generated a conservative document that may underestimate the changes that will result from a warming world.

Providing compelling evidence that global warming is accelerating, scientists announced Thursday that this winter was the hottest on record - and that surface temperatures around the world have beenincreasing at three times the rate they were before 1976.

Recent observations of downward solar radiation fluxes at Earth'ssurface have shown a recovery from the previous decline knownas global "dimming", with the "brightening" beginning around1990. The increasing amount of sunlight at the surface profoundlyaffects climate and may represent certain diminished counterbalancesto greenhouse gas warming, thereby making the warming trendmore evident during the past decade.

Hundreds of millions of people will not have enough water within a couple of decades as the harmful effects of global warming already start to appear, top scientists will say next month. At the same time, tens of millions of people will be flooded out of their homes each year as the Earth reels from rising temperatures and sea levels, according to portions of a draft of an international scientific report obtained by The Associated Press.

Declaring there is "no more time for delay," an international panel of scientists urged the world's nations Tuesday to stave off climate-change "catastrophe" by boosting clean-energy research and sharply cutting industrial emissions that fuel global warming.

January of 2007 was by far the hottest January ever. The broken record was fueled by a waning El Nino and a gradually warming world. The month broke the previous record by 0.81 degrees F. although duch records are normally broken by hundredths of a degree at a time.

"A broad array of scientists, including authors of the report and independent experts, said the latest analysis was the most sobering view yet of a century in which thousands of years of relatively stable climate conditions will suddenly be replaced by a new normalcy of continual change." (The New York Times)

The melting ice sheets in Greenland and Antarctica are a fairly recent development that has taken scientists by surprise. They don't know how to predict its effects in their computer models. But many fear it will mean the world's coastlines are swamped much earlier than most predict.

A combination of global warming and the El Niño weather system is set to make 2007 the warmest year on record with far-reaching consequences for the planet, one of Britain's leading climate experts has warned.

The IPCC's fourth assessment report, to be published in February, reports that the level of carbon dioxide in the atmosphere has accelerated in the past five years. It also predicts that temperatures will rise by up to 4.5 C during the next 100 years, bringing more frequent heat waves and storms. But the panel has lowered predictions of how much sea levels will rise in comparison with its last report in 2001.Climate change sceptics are expected to seize on the revised figures as evidence that action to combat global warming is less urgent.

The earth has a fever that could boost temperatures by 8 degrees Celsius making large parts of the surface uninhabitable and threatening billions of peoples' lives, according to British scientist James Lovelock.

The rise in humanity's emissions of carbon dioxide has accelerated sharply, according to a new analysis. The Global Carbon Project says that emissions were rising by less than 1% annually up to the year 2000, but are now rising at 2.5% per year.

The rise in concentrations of the greenhouse gas methane in the atmosphere has slowed down considerably in recent years, research suggests. Scientists say levels have been stable for about seven years following a steep rise during the last century.

Nobel Laureate Paul Crutzen and leading climatologist Tom M.L. Wigley proposed putting up an "umbrella" of aerosols to help cool the planet. The measure reflects the growing desperation in the scientific community about the build-up of atmospheric CO2.

The world - especially the Western United States, the Mediterranean region and Brazil - will likely suffer more extended droughts, heavy rainfalls and longer heat waves over the next century because of global warming, a new study forecasts.

For those who love New England's mild summer weather, scientists have some advice: enjoy it while you can. If greenhouse gas emissions continue on their current course, Massachusetts may feel more like sultry South Carolina by century's end, researchers said on Wednesday in a report on clear signs of global warming in the US Northeast.

Drought threatening the lives of millions will spread across half the land surface of the Earth in the coming century because of global warming, according to new predictions from Britain's leading climate scientists

The planet's temperature has climbed to levels not seen in about 12,000 years. The warming has also propelled plant and animal migrationss, researchers report in Tuesday's issue of Proceedings of the National Academy of Sciences.

Levels of the potent greenhouse gas methane are on the rise and could accelerate global warming, scientists said Thursday. Drought in recent years reduced methane emissions from natural sources and masked the impact of methane increases from human activities.

The variations measured from spacecraft since 1978 are too small to have contributed appreciably to accelerated global warming over the past 30 years. In this Review, we show that detailed analysis of these small output variations has greatly advanced our understanding of solar luminosity change, and this new understanding indicates that brightening of the Sun is unlikely to have had a significant influence on global warming since the seventeenth century.

Methane -- a greenhouse gas 23 times more powerful than carbon dioxide -- is being released from the permafrost at a rate five times faster than thought, according to a study being published Thursday in the journal Nature. The findings are based on new, more accurate measuring techniques. Global warming gases trapped in the soil are bubbling out of the thawing permafrost in amounts far higher than previously thought and may trigger what researchers warn is a climate time bomb.

The rapid rise in greenhouse gases over the past century is unprecedented in at least 800,000 years, according to a study of the oldest Antarctic ice core which highlights the reality of climate change. Air bubbles trapped in ice for hundreds of thousands of years have revealed that humans are changing the composition of the atmosphere in a manner that has no known natural parallel.

More than half of the world's major forests will be lost if global temperatures rise by an average of 3C or more by the end of the century. Extreme floods, forest fires and droughts will also become more common according to the most comprehensive analysis yet of the potential effects of human-made global warming.

The chemicals that replaced CFCs are better for the ozone layer, but do little to help global warming. These chemicals, too, act as a reflective layer in the atmosphere that traps heat like a greenhouse.

Heat waves like those that have scorched Europe and the United States in recent weeks are becoming more frequent because of global warming, say scientists who have studied decades of weather records and computer models of past, present and future climate.

Images of swamped homes in the U.S. Northeast deepened suspicions over global warming, giving ammunition to scientists and others who say greenhouse gas-spewing cars and factories are fueling extreme weather.

Most of the United States is getting wetter, thanks to global warming. Most of the continental United States is getting wetter while droughts are getting briefer and rarer, say scientists who have analyzed and modeled continental US stream flows and soil moisture data from 1925 to 2003.

Global warming accounted for around half of the extra hurricane-fueling warmth in the waters of the tropical North Atlantic in 2005, while natural cycles were only a minor factor, according to a new analysis the National Center for Atmospheric Research (NCAR). The findings were also endorsed by the American Geophysical Union and the National Science Foundation.

The nation's premier science policy body on Thursday threw its weight behind controversial data and voiced a "high level of confidence" that Earth is the hottest it has been in at least 400 years, possibly even longer. A panel convened of the National Research Council told lawmakers that the Earth is running a fever and that "human activities are responsible for much of the recent warming."

Researchers worry that if they cannot recall the distant climatic past, the world may be condemned to repeat it. And repeating the warmth of the early Pliocene epoch of 3 million to 4 million years ago would be a shocker. With no more carbon dioxide warming the greenhouse than today, the globe was a good 3°C warmer, and sea level was a whopping 25 meters higher. But how could such a modest stock of greenhouse gas fuel such warming? Unfortunately, no one knows.

Cleaner air and more Atlantic hurricanes may come as a pair, according to a new study comparing rising global sea surface temperatures with sun-blocking pollution particles. The recent decline of small manmade pollution particles in the North Atlantic might be allowing hurricane activity to catch up with the effects of global warming.

Researchers quantifying the effects of earlier releases of carbon dioxide and methane project that these current feedbacks will generate temperature increases later in this century that that may be significantly higher than what current climate models predict.

The extent of global warming is unprecedented in the last 20,000 years and it is "very likely" that greenhouse gas forcing has been the dominant cause of the observed warming of globally averaged temperatures in the last 50 years.

The world is likely to suffer a temperature rise of more than 3C, says the UK government's chief scientist. That would cause drought and famine and threaten millions of lives, said Professor David King in a report based on computer predictions.

The Earth's temperature, with rapid global warming over the past 30 years, is now passing through the peak level of the Holocene, a period of relatively stable climate that has existed for more than 10,000 years. Further warming of more than one degree Celsius will make the Earth warmer than it has been in a million years.

Human activities are releasing greenhouse gases more than 30 times faster than the rate of emissions that triggered a period of extreme global warming in the Earth's past, according to an expert on ancient climates.

Global warming in the past century has been greater than any other shift in the world's climate over the past 1200 years, researchers have reported. The analysis of data from tree rings, shell fossils, ice cores and temperature measurements shows the current warming trend is the most extensive change - warm or cold - since the time of the Vikings.

2005 was the warmest recorded on Earth's surface, and it was unusually hot in the Arctic, US space agency NASA said. All five of the hottest years since modern record-keeping began in the 1890s occurred within the last decade, according to analysis by NASA's Goddard Institute for Space Studies.

An ice core about two miles long the oldest frozen sample ever drilled from the underbelly of Antarctica shows that at no time in the last 650,000 years have levels of the greenhouse gases carbon dioxide and methane been as high as they are today.

Water vapour rather than carbon dioxide in the atmosphere is the main reason why Europe's climate is warming, according to a new study. The scientists say that rising temperatures caused by greenhouse gases are increasing humidity, which in turn amplifies the temperature rise.

Extreme weather events -- including heat waves, floods and drought -- are likely to become more common over the next century in the United States because of human-generated greenhouse gas emissions, according to a new study by Purdue University researchers.

Tropical storms have become significantly more intense in both the Atlantic and Pacific oceans during the past 30 years. Kerry Emanuel, an atmospheric researcher at the Massachusetts Institute of Technology, reports that tropical storms' overall intensity has increased by about 50 percent since the mid-1970s.

Two independent studies have found errors in previous satellite and balloon data . A third study shows that when the errors are taken into account, the troposphere actually got warmer -- a warming trend that agrees with the warmer observed surface temperatures and conforms to predictions in recent computer models.

The Earth is absorbing more energy from the Sun than it is giving back into space, according to a new study by climate scientists in the US. They base their findings on computer models of climate, and on measurements of temperature in the oceans. The group describes its results as "the smoking gun that we were looking for", removing any doubt that human activities are warming the planet.

In March, 2005, the atmospheric CO2 level surpassed 380 ppm -- by far the highest it has been in thousands of years. While it's increasing regularly, the rise isn't always steady, as indicated by the recent spike.

Since the Montreal Protocol went into effect in 1997, the substitutes for ozone-destroying CFCs have accounted for about five percent of man-made greenhouse gas emissions, said the report from the United Nations Environment Programme.

Scientists at a global warming conference say they see potential triggers for runaway climate change, but admit that when and how these notional doomsdays may be unleashed are debatable or quite unknown. The theoretical triggers are the apocalyptic side to global warming, making a lie of the common perception of it as an incremental threat that will rise predictably, like a straight line on a graph.

The largest ever climate-change experiment reveals that scientists may have dramatically underestimated the threat of global warming.The study by British scientists, which is published today, found the planet's global temperature could climb by between 2C and 11C because of skyrocketing levels of greenhouse gases such as carbon dioxide. That more than doubles the current prediction of a 1.4C to 4.5C rise this century.

The percentage of Earth's land area stricken by serious drought more than doubled from the 1970s to the early 2000s. Widespread drying occurred over much of Europe and Asia, Canada, western and southern Africa, and eastern Australia. Rising global temperatures appear to be a major factor, says the lead author of the study by the National Center for Atmospheric Research.

Global warming is set to continue, and bring with it an increase in extreme weather such as hurricanes and droughts, scientists from the United Nations' World Meteorological Organisation warned on Wednesday. The year 2004 is set to finish as the fourth-warmest since record-keeping began in 1861, fitting a pattern that has placed nine of the past 10 years among the warmest on record, the WMO said in its annual global climate report.

By 2050 heatwaves like that of 2003, which killed 15,000 in Europe and pushed British temperatures above 38C (100F) for the first time, will seem "unusually cool", the Hadley Centre for Climate Change says. The Centre estimates that average temperatures will rise by 3.5C, well above the 2C which the EU says is the limit to avoid catastrophic global warming.

October 2004 was the warmest October since record keeping began in 1880. February was the second hottest and March the third hottest on record. The average global temperature for the first 10 months of the year-14.57 degrees Celsius (58.22 degrees Fahrenheit)-makes 2004 the fourth warmest year on record.

When the world warms, key ecosystems may be tipped out of balance, creating a whole new set of climatic challenges. Vast icesheets may melt, sea levels will rise and, faced with a new climate, species will have to adapt, move or perish. Yet the precise details of how any of it will happen are unknown. Climate scientists say they have identified a dozen weak links around the world - regions where global warming could bring about the sudden collapse of vital ecosystems, the effects of which will be felt far afield.

Recent storms, droughts and heat waves are probably being caused by global warming, which means the effects of climate change are coming faster than anyone had feared, climate experts said on Thursday. Ice is melting faster than anyone predicted in the Antarctic and Greenland, ocean currents are changing and the seas are warming, the experts said.

The UK government's leading scientist says levels of carbon dioxide in the atmosphere already represent a danger. Professor Sir David King told a London audience the world had to adapt to prepare for significant changes ahead, and also to reduce greenhouse gases. He said climate change was "the most serious issue facing us this century and beyond", needing global solutions.

The rate at which global warming gases are accumulating in the atmosphere has taken a sharp leap upwards, leading to fears that the devastating effects of climate change may hit the world even sooner than has been predicted.

Global warming is likely to produce a significant increase in the intensity snd rainfall of hurricanes in coming decades, according to the most comprehensive computer analysis done so far. Following the battering of the US by Hurricanes Charley, Frances, Ivan and Jeanne, weather trackers are sounding the alarm. The arrival of hurricanes like Charley and Frances within weeks of each other is a rare anomaly, but some meteorologists say more storms like Frances -- both very intense and very large -- are possible.

The world has barely begun to recognise the danger of setting off rapid and irreversible changes in some crucial natural systems, a scientist says. Professor John Schellnhuber says the most important environmental issues for humans are among the least understood.

Heat waves like those that have hit Paris and Chicago in recent years are likely to get worse, roasting more and more cities with ever-higher temperatures, climate researchers predicted Thursday. The forecast means misery for many, and hotter weather can affect crops, drive up fuel prices, and can kill the old and weak. The heat wave that hit France a year ago killed an estimated 15,000 people.A similar heat wave that hit the Midwest last year damaged the corn and soy crops, and 739 people died in a heat wave that broiled Chicago in 1995.

No need to journey to the Arctic to find evidence of global warming: Venture to Boston's Arnold Arboretum, where flowering trees like dogwoods and magnolias have been blooming more than a week earlier than a century ago. In a paper to be published by the American Journal of Botany this month, researchers document that spring-flowering trees and shrubs bloomed, on average, eight days earlier from 1980 to 2002 than they did from 1900 to 1920.

A vast belch of methane gas from beneath the North Atlantic 55 million years ago may have warmed the planet and hold clues to threats from an even faster modern surge in greenhouse gases, scientists said.

Scientists are claiming to have found compelling new evidence for global warming, finally demolishing the argument of sceptics who have denied the phenomenon is real. New analysis of satellite data has revealed that temperatures in a critical part of the atmosphere are rising much faster than previously thought, strengthening the worldwide consensus that the earth is warming up.

Australian scientists have found the Earth may be more resilient to global warming than first thought, and they say a warmer world means a wetter planet, encouraging more plants to grow and soak up greenhouse gases.

Cities and towns along the west coast of the US could be suffering from a serious water shortage by 2050, thanks to global warming. As Arctic sea ice melts, annual rainfall may drop by as much as 30 per cent from Seattle to Los Angeles, and inland as far as the Rocky Mountains.

Carbon dioxide, the gas largely blamed for global warming, has reached record-high levels in the atmosphere after growing at an accelerated pace in the past year. Average readings at the Mauna Loa Observatory, where carbon dioxide density peaks each northern winter, hovered around 379 parts per million compared with about 376 a year ago.

The disapparance of permafrost in the bogs of subarctic Sweden has led to significant changes in the vegetation and a subsequent increase in emission of the greenhouse gas methane. Methane is 25 times more potent than carbon dioxide as a greenhouse gas. At one site, researchers found an increase in methane emissions of from 20 to 60 percent over 1970 levels.

Work by a New Mexico researcher suggests global warming may be less severe than some predictions based on the build-up of atmospheric water vapor. But the research also undercuts an argument made by global warming skeptics that a lack of water vapor could cool the planet.

The thinning of the ozone layer over the Arctic could be much worse than we thought, because of a side-effect of global warming. If the upper reaches of the Arctic atmosphere get colder - a predicted consequence of climate change - then the rate of ozone depletion could be three times greater than currently forecast.

Scientists have found strong new evidence that carbon dioxide, the main smokestack and tailpipe emission linked to global warming, is cooling and shrinking the atmosphere's outermost layers in ways that could aid as well as endanger space activities. The average density of the air in the region more than 60 miles up -- just a trillionth of that near the surface -- has dropped 10 percent over the last 36 years, and it could decline by a total of 50 percent by the end of the century, scientists at the Naval Research Laboratory in Washington report.

2003 tied for the world's second hottest year, according to new federal government data released Thursday. In what meteorologists say is new evidence that global warming is real and worsening, the world's average temperature last year was 58.03 degrees Fahrenheit, according to the National Climatic Data Center in Asheville, N.C. That's 1.03 degrees warmer than the 124-year world average.

There can be no doubt that global warming is real and is being caused by people, two top U.S. government climate experts said.Industrial emissions are a leading cause, they say - contradicting critics, already in the minority, who argue that climate change could be caused by mostly natural forces. The likely result is more frequent heat waves, droughts, extreme precipitation events, and related impacts, e.g., wildfires, heat stress, vegetation changes, and sea-level rise.

Scientists at the University of Maryland and the National Oceanic and Atmospheric Administration (NOAA) said they believe satellite measurements of the temperature of the middle atmosphere show a warming trend of about one-fourth of a degree Celsius per decade since 1978. That's close to the trends predicted in some computer models of global warming and reported by studies of ground-based thermometer records.

For nearly a decade, critics who dispute global warming have pointed to a single source of data to prove climate change isn't real: satellite measurements of the atmosphere's temperature. But a new analysis of satellite-based temperatures has thrown doubt onto that conclusion. The new inquiry shows significant warming of the upper atmosphere. The temperature rise is nine times larger than shown in previous studies and meshes more closely with other global warming findings, like melting glaciers, warming oceans and, perhaps most importantly, computer models of global climate.

Soot mostly from diesel engines is blocking snow and ice from reflecting sunlight, which is contributing to "near worldwide melting of ice" and as much as a quarter of all observed global warming, top NASA scientists say. James Hansen, director of National Aeronautic and Space Administration's Goddard Institute for Space Studies, and Nazarenko, a staff associate there, found soot is twice as potent as carbon dioxide in changing global surface air temperatures in the Arctic and the Northern Hemisphere.

After a 200-year rise driven mainly by human activities, atmospheric levels of methane, the second most important greenhouse gas, have stopped growing, scientists are reporting. Climate experts said the stabilization of methane, though probably temporary, is important evidence that steps to curb emissions could slow global warming even as disputes persist over what to do about carbon dioxide, the dominant greenhouse gas.

One of the last gaps in the evidence pointing to a human cause for global warming appears to be closing. A re-examination of 24 years of data from weather satellites has found that temperatures are rising in the lower layer of the atmosphere, called the troposphere, at a rate that is consistent with what has been measured at the earth's surface.

Climate change caused by human activity has been detected on a local level, an international group of scientists says.The researchers compared temperatures in North America between 1900 and 1999 with what one might expect if man had - and had not - had an influence. In the last 50 years, the rise in temperature is just what one would predict if man-made greenhouse gases were having an impact.

Over the past 40 years, climate has warmed over much of the Southern Hemisphere. The circumpolar westerly winds have also increased in strength, as a result of increasing atmospheric pressure at mid-latitudes and decreasing pressure and temperatures at high latitudes. These observed changes in Southern Hemisphere climate at high latitudes have a distinct seasonal structure, with largest amplitude in late spring and summer. Now new research indicates they may be caused by stratospheric ozone depletion over Antarctica in spring.

Oil and gas drilling across much of the Southwest produces far more methane emissions linked to global warming than previously realized.Researchers found about twice as much methane as expected, suggesting the United States and other nations have grossly underestimated global releases of the greenhouse gas.

Australia may be facing a permanent drought because of an accelerating vortex of winds whipping around the Antarctic that threatens to disrupt rainfall, scientists. Spinning faster and tighter, the 100 mile an hour jetstream is pulling climate bands south and dragging rain from Australia into the Southern Ocean, they say. They attribute the phenomenon to global warming and loss of the ozone layer over Antarctica.

The earth is warmer now than it has been at any time in the past 2,000 years, the most comprehensive study of climatic history has revealed. Confirming the worst fears of environmental scientists, the newly published findings are a blow to sceptics who maintain that global warming is part of the natural climatic cycle rather than a consequence of human industrial activity.

What caused the ice ages that have punctuated our planet's history for the past 2 million years? We badly need to know, a recent workshop of the world's top climate scientists concluded, because it could help us predict how our planet will respond to climate change in the coming decades. The answer "may help us decide if we are pushing the system to the extent that we risk a catastrophe," the conference concluded.

In an astonishing announcement on global warming and extreme weather, the World Meteorological Organisation signalled last night that the world's weather is going haywire.In a startling report, the WMO, which normally produces detailed scientific reports and staid statistics at the year's end, highlighted record extremes in weather and climate occurring all over the world in recent weeks, from Switzerland's hottest-ever June to a record month for tornadoes in the United States - and linked them to climate change.

Greenhouse gas increases already blamed for global warming also may be
shifting wind and rainfall patterns in the Northern Hemisphere by changing the
atmospheric pressure, according to a new study.The research suggests that pressure changes account for increased rainfall in
the Pacific Northwest and Britain, warmer winters in France, and drier weather
in Spain. "It will probably make winters milder in most parts of the Northern
Hemisphere," said Nathan Gillett of the University of Victoria in British
Columbia, who led the study published in the journal Nature.

Researchers at the Lawrence Livermore National Laboratory
have discovered another fingerprint of human effects on global climate. Recent research has shown that increases in the height of the tropopause over
the past two decades are directly linked to ozone depletion and increased
greenhouse gases. This research undercuts claims by greenhouse skeptics that no warming has
occurred during the last two decades. Tropopause height provides independent evidence of
the reality of recent warming of the troposphere.

2002 has been the second warmest since 1860, extending a quarter-century pattern of accelerated global warming linked to greenhouse gas emissions, United Nations scientists said on Tuesday. The World Meteorological Organisation (WMO), a United Nations agency, said that 1998 remained the hottest year on record, with 2002 surpassing last year as the next warmest. The 10 warmest years had all occurred since 1987, nine since 1990.

Scientists in Canada say they have found evidence that the west of the
country has warmed significantly over the last 150 years. Tthe evidence comes from a study of snow accumulation on Canada's
highest mountain. The build-up of snow they have detected there has been most
marked over the last decade. The scientists say their findings are consistent with other research
suggesting the Earth is warming.

Wildfires that scorched parts of
Indonesia in 1997 spewed as much carbon into the atmosphere as the entire
planet's biosphere removes from it in a year, shows new research published this
week. The fires, which destroyed thousands of forest acres and left peat bogs
smoldering for months, released as much as 2.6 billion metric tons of carbon -
mostly in the form of the greenhouse gas carbon dioxide (CO2) - into the
atmosphere.

A Spanish scientist says global warming may be to blame for giant
blocks of ice which fall from clear skies and rip gaping holes in cars and
houses. Jesus Martinez-Frias fears the formation of these hailstone-like blocks on clear days could be
a worrying symptom of climate change.

Black carbon soot from coal burning, diesel engines, open fires,
and other sources is contributing to global warming and climate change in China
and India, researchers report. In a study appearing in Friday's issue of the Science magazine,
researchers Surabi Menon and James Hansen said:"If our interpretation is correct, then reducing the amount of black carbon or soot may help diminish the intensity of floods in the south and droughts in the northern areas of China, in addition to having human health benefits."

British seasons are becoming increasingly muddled, say conservationists. Spring was three weeks early this year and autumn is likely to be late. Said Dr.Tim Sparks of the CEH: "The majority of climate scientists would agree that there are already signs
of a warming climate and this is having a knock-on effect on our plants and
animals."

New research indicates that air pollution from North America and Europe has exacerbated drought in countries
south of the Sahara. There are also warnings that growing industrialisation in India and China is
likely to create the same problems on the Indian subcontinent – with potentially
disastrous effects for millions more people. According to a report in New Scientist magazine, climate
modelling studies by scientists in Australia and Canada have fingered the clouds
of sulphur poured out by vehicles and power stations for pushing the Saharan rain-belt south.

Planet earth is warming up faster than previously
expected. Dying forests, expanding deserts and rising sea levels would wreak havoc to
human and animal lives sooner than anticipated as global warming was
accelerating, said Geoff Jenkins, head of the Hadley Center for Climate
Prediction and Research.

The forecast for central and northern Europe is for more extremely
wet winters over the next 100 years, thanks to global warming and rising levels of carbon dioxide (CO2). In a separate report in Nature, researchers at the U.S. Geological Survey warned of the possibility of
more great floods in very large river basins around the globe over the next 100
years. "We find that the frequency of great floods increased substantially during
the 20th century," they said in the report, adding the trend was likely to
continue.

The Earth's temperature in the year 2001 is expected to be the
second highest since global records began 140 years ago, the U.N. weather agency
said Tuesday, more proof of global warming caused by humans. The World
Meteorological Organization said the warming temperatures led to an increase in
the severity and frequency of storms and droughts and other unusual weather
conditions. "Temperatures are getting hotter, and they are getting
hotter faster now than at any time in the past," said Michel Jarraud, the
organization's deputy secretary-general.

Releases of carbon dioxide and other so-called ''greenhouse gases'' could
trigger an abrupt and dramatic change in global temperatures that governments
are unprepared to cope with. In a report released yesterday in Washington by the National Research
Council, the research arm of the National Academy of Sciences, a panel of 11
scientists examined the possibility of abrupt climate change, in which small
events can bring on rapid and great consequences.

Researchers at Lawrence
Livermore National Laboratory (LLNL) have discovered that large volcanic
eruptions cooled the lower layers of the atmosphere over the past 20 years,
masking the effects of global warming. This research undercuts claims by greenhouse skeptics that no warming has
occurred during the last two decades. These claims are based on satellite
measurements of temperatures in the lower troposphere, which show little or no
warming since the beginning of the satellite record in 1979.

Scientists have dispelled any lingering doubts about the
increase of greenhouse gases in the atmosphere with new evidence from
satellites orbiting the Earth. New sets of data taken 27 years apart from two satellites orbiting the Earth
have now provided the first observational evidence from space of a rise in
greenhouse gases.

Tropical island paradises and glistening Alpine skiing retreats
may be lost to future generations, while melting ice caps in polar regions could
unleash climate changes that would continue for centuries, according to a U.N.
report released Feb, 19, 2001.

In the most forceful warning yet on the threat of global
warming, an international panel of hundreds of scientists issued a report predicting brutal droughts, floods and violent storms across the planet over the
next century because air pollution is causing surface temperatures to rise
faster than anticipated, according to reports from Reuters, the Associated Press, The Washington Post and The New York Times.

Scientists say they have detected wide swings and, most recently, a sharp
drop in atmospheric concentrations of chemicals that naturally purge the air of
many kinds of contaminants and methane, a powerful heat-trapping greenhouse gas. The scientists suspect that the decline is related to human
activity.

Global warming may boost world temperatures by up to 11 degrees Fahrenheit by
the end of the 21st century, a figure substantially higher than previous
estimates,according to a group of climate scientists sponsored by the United Nations.Moreover,"there is now stronger evidence for human influence on global
climate," the scientists concluded in their preliminary report, which was
distributed to more than 100 governments this week for review.

SYDNEY - The discovery in a core of ancient polar ice of evidence of a sudden
Antarctic temperature rise thousands of years ago has added fuel to the debate
on global warming. Scientists working on an ice core taken several miles
beneath the surface found the first evidence of rapid warming in the Antarctic. It suggests a temperature spike of around four degrees Celsius took place in
the south pole region over about a decade 19,000 years ago. "That's a significant temperature change (over) about a decade... Pretty
phenomenal," said Dr David Etheridge, a scientist with Australia's Commonwealth
Scientific and Industrial Research Organisation (CSIRO).

Heavy Climate Impacts Forecast for Southern EuropeNorthern Europe and Britain can
expect more flooding and torrential rains in the years to come but southern
Europe will bear the brunt of the impact of global warming with water shortages,
forest fires and desertification.

With current atmospheric carbon concentrations at a level not seen for 420,000 years -- and with the carbon-absorption capacity of deep oceans diminishing and the limited capacity of terrestrial carbon sinks, humanity must come up with a large-scale systems approach to reducing carbon. Natural sinks are unable to assimilate human-generated carbon dioxide.

As the global
climate changes, extreme weather events such as droughts, floods, heat waves,
heavy rainfall, tropical storms and hurricanes are expected to increase. At the same time, extreme weather events have had increasing impact on human
health, welfare, and financial losses. This trend is likely to become more
intense in the years to come.

Soot, the familiar black residue that coats fireplaces and darkens truck
exhaust, may be a leading cause of global warming. A study in the current issue
of the journal Nature indicates that soot may be the second biggest
contributor to global warming - just behind the greenhouse gas carbon dioxide.

Forecasts of climate change are inevitably uncertain. It is essential to quantify the risk of significant departures from the predicted
response to a given emission scenario.We expect global mean temperatures in the decade 2036–46 to be 1–2.5 K (1.8 to 4.5 degrees F.) warmer
than in pre-industrial times under a 'business as usual' emission scenario. This
range is relatively robust to errors in the models' climate sensitivity, rate of
oceanic heat uptake or global response to sulphate aerosols as long as these
errors are persistent over time.

An influential expert on global warming who for nearly 20 years has pressed
countries to cut emissions of carbon dioxide and other heat-trapping greenhouse
gases now says the quickest way to slow warming is to
cut other heat-trapping greenhouse gases first.

We conclude that the effects of emissions of
CO2 and other greenhouse gases on the global climate are becoming
increasingly visible. This includes changes in temperature, precipitation, sea
level rise, atmospheric circulation patterns, and ecosystems. For many areas on
Earth these changes are becoming manifest through changes in the frequency and
the intensity of extreme weather events. We conclude with reasonable but no
absolute confidence that human induced climate change is now affecting the
geographic pattern, the frequency, and the intensity of extreme weather events.

Global warming is likely to take place 50 per cent faster and result in much more damage than previously thought, according to remarkable new computer predictions by British scientists. The new scenario implies a grim future for billions of people around the globe, with even more damaging impacts than have so far been expected in terms of droughts, extreme weather events such as hurricanes, rainstorms and flooding, and sea-level rise.

The Earth's surface is warming at an "unprecedented rate" that was not
expected to be seen until well into the 21st century. Throughout much of the 20th century, warming occurred at a rate of just over
1 degree per century. But since 1976, warming has occurred at a rate of "nearly
4 degrees per century." According to Tom Karl, the National Oceanic and
Atmospheric Administration climatologist who led the study, the sudden spike may
indicate a "change point" at which the Earth's surface begins warming at a
faster rate.

A new analysis of the climate of the last 1,000 years suggests that human
activity is the dominant force behind the sharp global warming trend seen in the
20th century. The study, by Dr. Thomas J. Crowley, a geologist at Texas A&M University,
found that natural factors, like fluctuations in sunshine or volcanic activity,
were powerful influences on temperatures in past centuries. But he found that
they account for only 25 percent of the warming since 1900. The lion's share, he
said, can be attributed to human influences, particularly to rising levels of
carbon dioxide and other heat-trapping "greenhouse gases" that come from the
burning of fuels and forests.

For the past several years, an international panel of climate scientists has
been testing alternatives to the idea that people are affecting global climate. But none of those factors fit the past
century's observed warming as well as the explanation they suggested in 1995: an
increase in greenhouse gases generated by human activity. So last week, the
group, the United Nations-sponsored Intergovernmental Panel on Climate Change
(IPCC), released the draft of a new report concluding "that there has been a
discernible human influence on global climate" -- the strongest official
pronouncement yet that human-induced warming is real.

A panel of scientists reviewing discrepancies between surface and upper-level temperatures affirms that the warming of the Earth is real and that its rate is increasing. The warming trend in global-mean surface temperatures over the past two
decades ''is undoubtedly real and is substantially greater than the average rate
of warming during the 20th century,'' said the 11-member panel of the National
Academy of Sciences.

The protective ozone layer that shields the Earth from the sun's
radiation may not be recovering from depletion it has suffered over the Arctic
region as quickly as scientists once thought.More polar stratospheric clouds, which have been known to accelerate ozone
loss, have been forming above the North Pole, according to a scientist at NASA's Ames Research Center.

Smoke from forest fires may
reduce rainfall, the National Aeronautics and Space Administration (NASA)
reports. Observations
last year led NASA scientists to
determine that smoke shuts down normal rain producing processes in tropical
clouds.

Health-Threatening Heat and Humidity Rises
Extreme summer heat and humidity of the kind most
threatening to health have become more frequent in the United States over the
last half century, two Federal researchers say. According to their study, in the
Dec. 10, 1998 issue of the journal Nature, the frequency of extremely hot, humid
days and of heat waves lasting several days increased substantially from 1949 to
1995. In terms of the threat to health, however, another finding was especially
significant: The increase in heat stress was greater at night than in the
daytime.

Rising Temperatures Bring Earlier Springtimes
Spring is now arriving a week earlier
in the Northern Hemisphere than it did twenty years ago and rising atmospheric
temperatures are the most likely cause, according to researchers at the Scripps
Institution of Oceanography.

Earth Is Warmest in 12 Centuries
The warming of the Earth in this century is without precedent in at least
1,200 years and cannot be fully explained by any known combination of natural
forces, one of the federal government"s top climate scientists said.

Temperatures in the United States will finish 1999 as the
second-warmest on record since 1900, topped only by last year's mark. Americans will have experienced an average for
1999 of 55.7 degrees Fahrenheit. This follows 1998's record high of 56.4
degrees.

Scientists looking for signs of global warming should spend more time
scrutinizing Earth's weather circulation patterns, a new study suggests.Researchers who studied northern winters since mid-century found that a
weather pattern favoring typically milder winters was two to three times more
likely to arise in the mid-1990s than around 1950.

Models Project 40% Increase in US Precipitation
Carbon dioxide emissions over the next century could increase
wintertime precipitation in the U.S. Southwest and Great Plains by 40% as global
average temperature rises 3 degrees Fahrenheit (2 degrees Celsius), according to
latest results from a new climate system model developed at the National Center
for Atmospheric Research by NCAR, university, and other laboratory scientists.
Reducing the buildup of carbon dioxide concentrations over the next century by
one half largely dries up the extra rain and snow and slows the global
temperature rise to 2 degrees F (1.5 degrees C).

Temperature changes over the twentieth century cannot be explained by any
combination of natural variability and natural forcings alone, according
to a team of British scientists. While solar forcing may have contributed to the
temperature changes early in the century, the warming since the 1940s is due
definitely to human activities, according to findings published in the June 10,
1999 issue of the journal Nature.

Researchers released a report
strongly suggesting that the 1990s were the warmest decade of the millennium,
with 1998 the warmest year so far. The researchers also found that the warming in the 20th
century counters a 1,000-year-long cooling trend, which makes the finding even more troublesome.

1997 Warmest Year in last 6001997 was the warmest the world has
experienced, going back at least to the century before Christopher Columbus
sailed.The new findings provide the clearest and most dramatic evidence that
the world is experiencing global warming caused by human activity.

1998 Called Hottest Year of Millenium
Based on studies of indirect evidence like the annual rings of trees,
Dr. Philip Jones believes 1998 to be not only the warmest year in the thermometer
record, but also the warmest year of the millennium.

Satellite Readings Confirm Warming
The two-decade record of
satellite data has been distorted by the inevitable decay,
or lowering, of the satellites' orbits as they encounter atmospheric resistance.
Once this error is corrected,the satellite record shows the atmosphere has become warmer.

Rising Low Temperatures
The range between daytime high temperatures and nighttime low temperatures
is decreasing in much of the world -- a signature of "greenhouse" warming.

Changes in global average temperatures and of the seasonal cycle are strongly coupled to the concentration of atmospheric CO2. I estimate transfer functions from changes in atmospheric CO2 and from changes in solar irradiance to hemispheric temperatures that have been corrected for the effects of precession. They show that changes from CO2 over the last century are about three times larger than those from changes in solar irradiance. The increase in global average temperature during the last century is at least 20 times the SD of the residual temperature series left when the effects of CO2 and changes in solar irradiance are subtracted.